To introduce - I had some mates round this weekend and while they're not into free/libre games regularly, we all played some Nexuiz and had a blast

I've also been playing Tremulous for a while now, and so I couldn't help but wonder that you guys are using two different engines (though of course diversity has advantages as well).
I've had a bit of a look around, and I read that people reckon Nexuiz would look worse on the ioquake3 engine then on Darkplaces - is that still the case? Are there other reasons that speak against porting? And what reasons might Tremulous have for not switching to Darkplaces?
Thanks for your time,
a very curious Sean