I drive a lot, not as much as you, but I do about 25K annually and have switched between tanks of 87 and 93 octane. I get much better performance on the 93, and roughly 2MPG better gas mileage cruising between 75 and 80 MPH.
On 87 octane the car pulls a ridiculous amount of timing when it's hot out. It wasn't bad back in early March, but now there is a major difference between 87 and 93 right now.
Personally I'm done with 87 in my car for the summer at least.. I much rather price shop to find decent priced 93 (Costco or the local HEB gas stations are usually least expensive) than sacrifice the performance. In the hot Texas weather it really is a night and day difference. The car will be fine on 87 though if you want to save the coin. I go through about 2 tanks a week, and right now there's a 30 to 40 cent difference between gas grades right now.
I would say get a tank of 87 and drive around like you normally do... get the tank pretty empty then fill up with a good 93 like Shell and then go repeat your normal drive. The 93 is a lot more responsive and pulls stronger on the top end.