Hi Asbak!
Don’t use firewire enough here to know the M-Audio or Tascam. I’ve always been sort of wary of it for important “uninterrupted throughput” applications (but not like I am with USB). I’ve heard some things about certain FW interfaces polling the bus, or some other sort of brief processing, behind the heavy audio streaming, which has caused spikes and such for a few people, but that may well be old info from earlier chipsets or FW drivers. Also, make absolutely sure either of them isn’t known to drop off the host unexpectedly or ever go “undetected”. That’s actually my main fear of the newer “non-PCI” formats for audio. My multi-tracking needs are pretty modest (less than 15 simultaneous In’s, usually more like 8-12). On mixing I’m usually only a few, but they may be spread between the 3 banks of my 2408mk3.
I’ll toss in a vote for that Behringer. 
I grabbed one a while back, and haven’t had anything to gripe about. The pre’s IMHO, sounded better than my other cheap junk (MackieVLZ,Alesis12R,Symetrix528), and the only thing I noticed much of an improvement with, was a modified Symetrix SX-202, and the sounds were “different”, so the ADA may have even been better on certain things (didn’t get much listening in). It definitely won’t hinder most people, and ADAT converters are always welcomed these days. They give you lots of options on cheap computer cards, plus since they’re bi-directional, you can get a whole pile of returns going back to your tracking room for headphones or whatever.
If I were shopping right now, and needed 16 analogs, I’d almost be likely to go with (2) of the ADA’s and the cheapest multi-ADAT card I could get (with a good driver). I really only use the two control room outs on my interface, for my mains, and all the other i/o is in the tracking room via ADAT.
If you go FW, be sure to get some good online comments pertaining to specifically what you’re trying to do. You have to keep in mind that a lot of the FW and USB interfaces are bought and used by more musicians, where the throughput requirements may not be quite so heavy. With plans to stream 16 audio tracks at a decent rate/res., make sure you get somewhere with people who’ve used it for that. I’ve seen plenty of FW audio boxes listed on large systems, so I know you can do it, but I’m still sort of “old timey” about the internal cards. For good multi-analog DAW examples, the Nuendo hardware forum has some pretty heavy hitters. Some of their system profiles make me feel like I’m on a 386DX.
With whichever brand or model you pick, you obviously should do what it takes to get genuine “honest” firsthand user feedback on it. Register for whatever user groups or forums they may have, and read some complaints by actual users and see how, or if, they were ultimately resolved. I’m really starting to hate the info you’ll get in most of the magazines these days, mainly due to a recent realization that a certain “unnamed” party, who holds a permanent monthly reservation on the most expensive (back cover) advertising slot, across ALL major recording and electronic music magazines, seems to have a public image with the media and music stores, which it has done very little to deserve. It goes way beyond that, but I’ll keep it out of here for now, and just try to make a few " unbiased", " impartial" shopping suggestions: Just make sure you get something which isn’t known to " fail" or " disappear" in any way, and which doesn’t use " lower quality parts" like cheap displays and pots, or poorly ventilated cases, which might be slightly more susceptible to " heat problems", further jeopardizing the lower quality components. Also, try to look into whether or not the company has " frequent returns for specific failures", possibly from " rushed production", or too many " corners cut in component cost or design". And try to find reports of anyone receiving multiple " defective units", or " poorly assembled" ones, or ones which may be " suspected" of being " refurbs", or " unsuccessful repairs", or " high failure rates" on recently purchased, out-of-warranty units, with very " few moving parts", which began " failing" or " malfunctioning", while merely " sitting in a rack". Also, make sure you get something from a manufacturer who is genuinely bi-platform, not like a Mac company who writes some " barely adequate drivers" and stamps Windows logos on all their stuff, while refusing to research or conform to any of the standard PC OS, audio, and plug protocols, or who stops developing after the first couple driver builds seem to somewhat work, and then " blatantly ignores" reports of any hardware or software specific incompatibility which many users appear to be suffering, while they scramble to prepare for the next line of " prematurely released" hardware, which has already been announced and advertised, or worse yet, discovers (or is informed of) some ridiculous, " convoluted workarounds or boot sequences" which " some" have reported " may sometimes work", so there’s no further need of any programming effort, or who will persist in draining the last drop of blood from any previously written driver code or software, rather than " rewriting" anything to make it " properly comply" with modern systems. And be careful with companies who won’t officially claim " support" or " compatibility" with current OS revisions or software, or with some of the " common chipsets or hardware" frequently found in modern Windows DAW’s, and who will " blame" those manufacturers or developers, and recommend against their use, or insist that they won’t work, in an effort to " avoid driver issues" or any further overdue tweaks to the driver code, while they move on to the " next product". And watch out for places with an " insufficient support staff", or techs who " know little to nothing about Windows PC’s", or who occasionally answer support questions with insulting " direct quotes from their poorly compiled FAQ", or with responses which prove they never actually read the customer’s question or details. And try to get a product which was " properly tested" on a " substantial" amount of " test systems" and " configurations". Oh yeah, and make sure you get something from a place which has " multiple phone lines", and who actually " responds to most emails or letters". And look for places who don’t allocate more resources to " advertising", " flashy packaging", or their " feature sets", than they do to " development & support". Then, the only other thing I can think of is to go with a manufacturer who has a decent " active presence" in their own " user community", and who’s staff is well regarded as being " knowledgeable , friendly, & easy to contact", by most everyone who’s needed their help.
I could probably come up with a couple brands I frequently hear good stuff about in the Nuendo forums, but unfortunately, right off the top of my head, I can’t really think of any particular manufacturer that I would recommend " not" buying anything from. ;D
Good Luck
George
