Would this reel do well on a 7'1" MH fast casting rod? I will use it with 15 pound Seaguar Invisx for spinnerbaits, finesse swim jigs, small trigs, and other MH stuff. Would 6.3 or 7.2 be best? Also, should I fear the small line capacity?

Its a great reel. i have 2, they always make every trip. I have the 6 ratio but for what you mentioned id get the 7

7.2, and it doesn't have a small line capacity, it holds more than enough

7.2 

Line capacity should only be an issue in bass fishing for a select few presentations (bombing big cranks or fishing big swimbaits for example). Even a giant largemouth is only going to pull a very small amount of drag compared to a lot of similar sized fish. Like has already been stated, it has about the average line capacity anyways. I'd go with the higher speed option for what you're wanting to do. 

2 hours ago, Bluebasser86 said:

Line capacity should only be an issue in bass fishing for a select few presentations (bombing big cranks or fishing big swimbaits for example). Even a giant largemouth is only going to pull a very small amount of drag compared to a lot of similar sized fish. Like has already been stated, it has about the average line capacity anyways. I'd go with the higher speed option for what you're wanting to do. 

What he said.

I fish with less than 70yds of line on all my reels.  Never had any issues.  7.2 sounds good for that.