First off, there is no drive channel on the Twin Reverb. It is all about clean headroom. Put simply, you can't get the tone to break up at all at normal to loud volume setting. I have never dimed my '65 reissue TR (kid of lame I know) but I am not even sure it would break up then.
The other amp has an independent drive channel. I have never played through one so I have no idea what it sounds like, I imagine the clean channel is close to that of the TR. No idea what the drive channel sounds like but I have never loved the drive channels of any Fenders I have heard.
Reliability has never been an issue for my TR.
Personally, I would go with the TR and use nice drive pedals for breaking up the signal. In the end, whichever amp gets your rocks off, that's the one to buy. Good luck.
There are only two mantras. Yum and yuk. Mine's yum.