T5s help to create a more even spread of light in larger tanks. With point source LEDs you can be left with dark zones due to most of the light coming from a small puck filled with diodes. Some people also swear by T5 light and think that corals grow better under it. Really what you do in terms of straight LED or hybrid depends on your goals for the system. What type of corals will you be keeping, how densely you are going to stock with coral, and what your aquascape looks like will all play in to what your best choice is. The two XR 30s should suffice for LPS, softies, and some easier SPS, but you will definitely have "dark" areas that are shadowed. A third XR30 and/or supplemental T5 lighting would be a good idea IMO. I am sure that more people will chime in on this with some specific T5 fixture recommendations. I don't have a lot of experience with T5s as I usually run exclusively LEDs but I have seen many tanks much more beautiful than mine that rely on T5 lighting.
