I have the T68 (which I had flashed to the T68i - the stock T68i color scheme looks a little to "sissy" to me).
Prior to that, I had the T39, which was a stellar unit. The optional extendable mast was excellent in fringe areas.
I use it conjuction with my iPaq 3870 (via bluetooth) and it works like a champ.
I bought my wife the Nokia 6310i (well, she got it after I decided I didn't like it) and other than in the RF department, I would say the T68i is the hands-down winner.
I believe the T68i is one of those rare products, like the empeg, that truly perform as billed and were well worth the price of admission...
Just my two drachmas...
Rob