I just use soulseeX because I could never get older versions of solarseek to work. soulseeX works great for me so I've never bothered to try any of the recent versions of solarseek.

Though the search function in soulseeX leaves a little to be desired, I don't remember the one in soulseek proper ever being all that great. That could be something that solarseek does better (i.e. more options), but I don't know.