I've had a pair now for about a year and have used them mostly on acoustic music mixes (lots of "new-music" / experimental classical stuff), and I'm honestly pretty ambivalent about them at this point. They're weird boxes. The feature set is great with lots of tonal variety and interestingly interactive controls. I like the novel approach to the control of the gain structure. The mix control and sidechain filter are also very simple and extremely useful controls which were in a way my main attraction to the design. There are a number of other interesting features and design elements that are unique and noteworthy, but I won't give a full book report here.
All of that being said, I've come to feel pretty unenthusiastic about the way the units sound when actually really compressing something! Well, that's far to general a statement. But, I guess what I mean is that most of the time, it begins to sound wrong to me as soon as you start to hit more than 4db of reduction. It starts to sound dark and closed in fast as it works harder and harder. I thought that these would be great for heavier compression and had hoped they'd have a bit of the TG1 sound; not at all. In my limited experience with them, the TG1s are pretty magical when they're smashing the crap out of certain things; the germs, not so much.
One factor in this is that, to my ears, the attack and release characteristics are weird. It can attack very quickly, but set to slow it doesn't really snap the way I look for in a parallel comp situation. Given the inclusion of the mix control, I thought this would be perfect for parallel compression on a drum sub, but it just doesn't pop the way, for example, a 2500 or 33609 does. On the other side, the release always seems a bit too slow for my taste. Set to "fast" it still gets pretty sluggish when doing even medium gain reduction.
FWIW, I don't think I've ever used it with the "mix" control set more than 50% wet.
My final gripe about them is that, contrary to what Wade has insisted elsewhere on these boards, they are in my experience quite noisy. I keep the input permanently at 11 (cute, right?) because that's really the only way to keep the noise down to a useable level. (The input control is an attenuator - if I'm not mistaken - so setting it at max actually inputs the signal at unity, requiring minimal amount of makeup gain.) This is not a matter of "well you know, compressors tend to bring up the noise" kind of thing. If I set them up so that bypassed and processed levels are basically matched and there's virtually no compression happening, the noise is still very noticeable when you switch the units "in".
This is especially true if you try to be aggressive with the "germanium drive" and "feedback" controls. This is one of the most interesting features of the unit - the way that its makeup amplifier can be pushed for a more colored sound and then attenuated by the feedback control which also imparts a certain characteristic. But getting creative with this quickly yields noise problems, and I guess you just have to figure out what's more important in a give situation - whatever tonal variety you get from tweaking these controls or the added noise that will result. Don't get me wrong - this is an issue which would likely never pose a problem in a rock or pop mix. I just tend to be sensitive to this stuff due to the nature of the material on which I typically work. Still, these are the only boxes in my rack for which that is the case. Maybe after a year, I'm still not using them correctly or something, but honestly if that's the learning curve on a compressor, something's wrong with the design.
In the end, I'm keeping them, and I use them pretty often for various things. I think that for the money they're very cool and flexible boxes. They definitely have a sound of their own, and I guess one can either love or hate that sound. They're definitely not my favorite sounding compressors by a long shot, but I do think they have a place and do things that no other designs do. If anything else, it's nice to see some unique and original designs out there.