With the next oil change, in about 500 miles, I'm going to change my transmission fluid. Last time I did it, about 15,000 miles ago, I used Syncromesh fluid. It's worked great, but I can tell that after only 15,000 miles the shifts are getting a little rougher. So I'm thinking about changing fluids. Does anyone have any ideas suggestions? It's my DD, but I do run it kind of hard. I was thinking about going back to Honda MTF, but last time I used it I was disappointed with it; the shifts were noticeably rougher then with Syncromesh.

Thanks for any suggestions.