For me, it's all about the bridge pickup. Throw whatever you want in the neck and middle positions, but a Tele with a bucker in the bridge...well, what's the point?
Though I have been wondering what an angled P90 in the bridge position would sound like. I've seen Teles with p90s, but they're always straight in the bridge, instead of the traditional slant.
I've seen that done... it looks kinda {censored}ed up... a bit like Mosrite looks wierd with a slanted PU up at the neck.
Tone wise... not much difference if any...
Not that there's anything wrong with a P90 at the bridge in a tele...I just don't think the slant makes much difference.