I had a 300i before going to the 500i, I listened for hours and never got fatigued. It was mated with a Krell CD player and the same Dynaudio in my signature. Krell is on the opposite end of the street than tubes but harsh it isn't. An advantage with Krell, Bryston, Parasound and that breed of high current amp it will sound "muscular" even at low volume. I still have my 500i but found I enjoy Conrad Johnson better. Keep in mind you don't listen at high volume and play the equipment you audition at that moderate level to see how it does.

I personally wouldn't recommend Maggies for Rock either but that's a personal decision. All I can say is you should listen first. Also, keep in mind that most every one uses a sub with Maggies, additional space and expense. Add that to their value and they become not such a value.

For you, at this point, as Ajani stated, the best thing would be to do some listening to get a feel for some of the gear.