Tact Pre Amps

Thinking of purchasing one of these. The 2.0S or 2.2XP. Cost is a factor. Can anyone weigh in as to whether it's worth the investment?

Depends on how good/bad your room is. I bought when to tame a really horrible listening room in a rented apartment, and it was worht every penny. I just upgraded my 2.2X to XP. The XP is more user friendly and fixes a lot of the software bugs in the 2.2 X, and allows you to measure the effect of the correction.....but the software stll needs work in some areas (e.g., curve editing nowhere near as nice as in the X software....). You will need a 2.2 if you are planning to use subwoofers..I think the 2.o has no subwoofer outputs. IMHO, the ability to seamlessly integrate subs with main speakers is one of the key selling points of the Tact 2.2
I've had a fully loaded RCS 2.0 for over six years. It really cleans up a lot of room problems. There are nine presets so I can create nine different corrections (though I really use only one). The difference between hearing your room with all the anomalies and hearing your room once it is corrected is shocking. It is a great tool. TacT put a lot of capability into the RCS but frankly, I'm not using it to it's fullest. You need to use the unit with a computer and really tweak my room using the TacT becomes to demanding for my computer-limited brain. I would suggest you get one and demo it for two weeks. Once you understand the set-up you can do a room correction in two minutes. That part is not difficult. I guarantee you WILL hear a difference. Whether you like it or not is why you must do a demo. Note: there is no tape loop so you must connect a recording device to a line level output that is controlled by the main volume. Any adjustment to the speakers means you adjust the level of your recording.

The Tact is not a easy to use gear if you want to get a good result... you will need to spend a lot of time to find the best settings.
Also the analog I/O are definitely bad, forget them if you want to get a good treble.
I think the 2.2X is better as there's a way to correct the signal only below 350Hz, you can't do that with the 2.0S and from my experience correction higher than 350Hz are not interesting... a few Echobusters panels are way better.
The Tact's A/D and D/A board get a LOT better after Aberdeen Components modifies them. My XP has all the mods Aberdeen offers, including power supply, motherboard, A/D boards, and D/A boards. They put the XP in a totally different class vs. stock. To note, with the XP you dont have to use a computer - everyhting is done inside the unit - although you can use a computer, and you will want eventually if you want to fine tune your settings.....