I've owned just about all the Jobo CPXX models, and now have the ATL2+. There is really no downside to a Jobo as far as I'm concerned, provided it's in good condition. Just about all the parts are available if you look hard enough. My enlarger and ATL are essentials in my darkroom, and I only develop B&W. It makes processing a breeze and keeps everything consistent from batch to batch. I also do all my printing (except toning) in the ATL. I can print from postcards up to 20x24 with amazing easy. I can't recommend them enough :)
I find the Jobo a huge advantage for B&W sheet film. Were I only developing small quatities of 120 or 35mm its usefulness would still outweigh its disadvantages. For me, that is. I don't think it is possible to make blanket statements about any system being right or not right for processing--that's something you have to decide for yourself.
Agitation is a variable that can be controlled with the Jobo. The ATL2+ has 4 different rotation speeds. Having said all that, of course the machine has limits. I try to keep development as simple and consistent as possible. In the end, it matches perfectly with the way I like to work in the darkroom. It may not be everyone's cup of tea....
No real downside, partcularly since it's free. A CPP2 will have great utility for someone without access to a full darkroom sink, even if only processing B&W. Terrific for E6, incidentally, so you'll not have any difficulty turning a buck on it should you decide it's not your preferred way to work. Might also mention that if it has one, the Lift can be a most useful accessory but it's quite a bit vulnerable when moving (suggest disassembly of the lift arm from the unit).
I have ended up using developers that work well with the Jobo, and adjusting my methods of shooting accordingly. I am willing to do this because the other tanks I have used (HP Combi and Yankee) don't do nearly so good a job with sheet film. If I want Diafine-type results, I use Acufine instead, which works fine in this unit. But I have not been in many circumstances in which xtol or D-76 won't do the job. My methods are not sophisticated or complicated enough that agitation control rules out the use of the Jobo. Even night photos, which I used to develop using a semi-stand method, I now subject to a version of the zone system and get better results with constant agitation. But again, it is what I am willing to do, and I say it just to show that it is possible.
Using the paterson 2 films requires at least 600ml.