Topspin anyone?

That is right. The topspin serve may be one of the most valuable serves to have in ones bag of serves. If you don't know how to hit a top-spin serve, you focus on peeling from left to right. Peel in an upward motion on the ball from 7 to 1 o'clock. It is really effective and can be one of your high percentage serves.

Where would Stefen Edberg be without it?

Where would be anyone without when you think about it? It has greatly improved my personal percentage of first serves and is quite effective since I am not that tall.

BTW Rick, I think I remember reading in another post where you used to string racquets. Is this correct? If so, I guess you got to see many different types of racquets in all various stages of wear (strings and body). I personally like my strings very taught for control and tend to have them restrung every other month or more when I play more regularly. Have fun.

Yes I do string racquets and sell them also. Racquet restringing is still a very personal thing amongst most players. There are a few rules I like to go by, but without knowing the type of player I am stringing for, I would not advise anyone on this forum. All that to say, try, if you can afford it, to use a multifibre string as opposed to a basic "syngut". The advantage in play is def. noticable. If you do play with basic "syngut" and you have played more than 8hrs.(I am being generous here) with them, I would restring. Usually the more fibers the more consistant the hit and the longer they will play consistantly. All this said again most playes at 4.0 and above will need to resting due to breakage probably before the 8hr. mark.
This information is very general in scope. If you want more specific info for you. Let me know.