I don't know of any p2p programs that use UDP, and certainly none that use ICMP.
WinMX uses UDP, and soon to learn what ICMP is.
I have seen more on WinMX than kazaa lite, and on MX i get better speeds on my dial-up, usually 5 to 7 kbps. kazaa lite does have a few files i have been looking for thou.
Bit torrent has been good to me, decent speeds (usually 5k down and 2k up)
now, if a P2P program was written i just want a few things, good contol over what im sharing like winmx 3.54 beta 1, but bad IP blocks like kazaa lite, and speeds of bit torrent and winmx alike. just impliment those 3 into 1 massavely cool ad-free and spy-free program. oh and lets not forget, a way to block sharing of child porn, cause im tired of people downloading off me who are sharing that trash.