Sedona and Oak Creek Canyon up the way in April can have snow (I have seen the interstate closed between Sedona turnoff and Flagstaff in April due to heavy snow) so keep that in mind. It is not hot at that time of year although can be pleasant--not pool weather.
Conquistador and Tucson are my favorites. I have been upgraded to casitas but some prefer rooms overlooking pool (too noisy for me). Tucson can also get cool in April but also can be warm--luck of the draw. If it is an El Nino year then expect rain and desert flower blooms. We found some ok eats fairly close by along North Oracle so it is not an epicurean wasteland.
Phoenix more likely to be warmest in April, perhaps hot for some. Definitely pool weather possibility. Tapatio cliffs is nice, perhaps a little sprawling -- got nice upgraded suite as Diamond last time there.
Seemed a bit away from the action like all these places--but that is part of the charm.