Should I be looking at temp control, regardless of basement good fortune?
For most ales, it sounds like you've already got good temperature control. As long as the temperature doesn't swing too much and you're happy with the beers you're brewing, why change things?
If you're worried about temperature rising too much you can use a swamp cooler. If you're worried about temperature swings, you can created an insulated box to put over your carboy.
The only reason I see for going to the expense of extra appliances and temperature controls is if you're wanting to go beyond ales and brew styles where you need either a chilly fermentation temperature and/or a period of cold conditioning.