Glad to hear you enjoyed your drives in the LS! As a proud owner of a 2000 LS V8 Sport, I concur with most of what you have mentioned. I belong to the LLSOC, and even though it's a membership site ($35/year), it's well worth it when it comes to the parts deals and events. If you were to pursue an LS, the best upgrades so far have been an intake and an exhaust, as no tuner has yet cracked the PCM for the LS, so modifications like turbos/superchargers are unavailable unless you swap in an S-Type R motor (around $20k).
As for reliability, so far I have had no major problems since I bought mine in May. In fact, the only work I know of on the car was some valve cover work for an oil leak.
If you have any other questions, please feel free to ask.
James