I have a 112TC.
It goes high enough. It goes OK speed-wise (slow is in the minds of the beholder). It is quite comfortable (making any speed issue a non-problem). It's heavy - but built well... the landing gear are trailing-link so it's harder to make a bad landing.
The only think that doesn't thrill me on the 112TC is that it's not a common engine. The straight 112s use IO360's, relatively common but somewhat underpowered.
The 114's (and later) use IO/TIO 540s. Higher gross weight, faster, still comfortable (key airframe difference to the 112B/112TC is wing length). Were I to do it again, I'd opt for the 114TC. For one person, the 112TC is OK. There is a version of the 114TC/115 that came with TKS K-ice.
Most parts are available. There's decent support, and some folks very passionate about the plane. Henning's right, there is a mod to change the angle of incidence to the elevator (which I have not done, so I can't speak to it's effectiveness). There are also a couple of engine mods available. Usual range of airframe mods are available, including VG's (I love mine...), gap seals (a couple of knots), turbonormalizing for the straight 112 series, etc.
The gear is hydraulic - power packs can be rebuilt. Folks that complain about rebuild quality often have had their rebuild done at Kelly.
No, it's not as fast as a Mooney, but it's far more roomy. Unlike a Bo' it's got two doors, which is handy with pax. It's stable & fun to fly (did my IPC last weekend & CFI noted that he was glad to be doing it in my plane...)