Revolution seems like a good choice, given that where you are, fleas and heartworms are pretty much a year-round problem, so an all-in-one makes perfect sense. I originally chose Sentinel because I really wanted to stick with the milbemycin oxime, and I really liked having one pill take care of both fleas and heartworm--much easier to remember just one pill than two. However, when it came time to reorder, I decided that it might be easier on Lerwick's system to break the meds up, and dose him for heartworm at the beginning of the month, and then do a topical flea/tick later in the month, which is why I "downgraded" to the plain Interceptor, and now use Frontline Plus for flea/tick.
Turns out that was a wise decision on my part, though not for any reason I had actually been considering. Sentinel was great with fleas, but this spring we discovered, it isn't the fleas we have to watch out for Lerwick... it's ticks! Sentinel doesn't guard against ticks, so I'd have had to find an additional tick medication anyway. I'm lucky in that TN isn't a high-risk state for Lyme... and of the 5 ticks we've found on him, all have been the lesser-evil dog tick... but still. Freaked me out plenty anyway. The problem for us is that we've got a cat, so some of the more effective "kills them immediately" type preventative/repellants are not options for us, as they are highly toxic to kitties.
I will have to consider switching heartworm meds when my current supply runs out in November, if Novartis hasn't gotten its act together by then.

Looking at the Revolution website, I see it guards against dog ticks as well as fleas, so I may be making a switch to Revolution when the current meds run out, too!