One thing you should remember is that the spectrum is not compatible with WHDLOAD.
Ah, but it does have a pass-through port, so as long as your RTG software is configured correctly to use it, it should be fine with native Amiga video.
@ thread
While P96 and CGX are the best options, EGS' one advantage is that it works on Kickstart 2. I've got an EGS Spectrum in a 2.x A3000. Yes, it is kludgy, but I think a lot of that is to work around the complete lack of non-native video support in 2.x. Kickstart 3 made some improvements in these areas, so P96 and CGX can integrate more smoothly.
One other cool thing about EGS is that it has built-in mode promotion support, so there's no need for a utility like ModePro if you're trying to force certain screens to use the Spectrum.