I have a 2.2XP and am currently using with a Yamamoto A-08s down to 60 hz or so and a SS amp below that. The overall result is excellent but I wouldn't rush into room correction unless you think you really need it. The XP, though being a "real time" device and easier to adjust than the earlier versions, invites constant tinkering and wondering whether optimization has been achieved. You have to ask "Do I like this?" rather than "Is this as good as it could be".
My unit is stock and I do not like the stock DAC's. It sounds much better digital-out to my Ack! 2.0. Eventually I will go to an Altmann which can handle 192 khz inputs with battery power and non-OS luvin' that is my decided preference.
The TacT units are expensive, even used. If you don't Need the room correction function, I'd venture there are better choices. On the other hand, if you're FR is all over the map and it's bothering your ears, take the plunge and prepare to be humbled for a while, as the learning curve is a bit painful.