I have some expierence with the hv30 and an hfs100 which is prtty much the same thing as the hfs10.
Well the big difference between the two is hv30 is tape and the hf s10 is flash memory. Personally I still enjoy tape and the capturing of tapes is not a big pain. I find it more of a pain to import the footage from my buddy's hfs100. So that is the first decision you got to make do you want solid state or tape?
Next is can your computer handle the footage? AVCHD which is the format the hf s10 records to requires a rather powerful computer somebody on here can give you more info on AVCHD, I don't know to much about it. AVCHD records in a bigger size 1920 by 1080 unlike HDV where it is 1440 by 1080. Anyway I think someone can give you more info on AVCHD or just google it.
If your thinking of going hv30 or hv40 there are few difference between them. The hv40 record true or native 24p which isn't ideal for skiing ,but nice for short films among other things. 24p if your just shooting is not very useful. That is the biggest difference the rest is useless stuff like a different record button or something like that...
Good Luck Choosing a camera!