Well it looks like part of my question has been answered (even if I did not specify the parts ).. it seems the only difference between the OM4 and T is the top and bottom plates and the use of the F280 flash to sync at any speed.
Considering I dont have the f280 flash, nor do I use high speed flash, I dont think I need the features of the T.
The second part is just the age of the camera.. the 4T's and 4Ti's were the latest versions of this model. Would one of these more recent cameras last longer than an older one, given both have CLA's?
Opinions are welcome, I know this is a not an exact science.