Ok, let me tell you about my experience on felucca during the 3 months Im playing on OSI Atlantic shard.
Fel is REALLY empty, you dont find ppl if you don't go to the pvp spots..(yew gate and champ). although I actually manageg to get Pk TWO times on felucca, one time was near Minoc city when I tried to go to mining there and the second one was on that swamp near britain city(and if you can believe me I can tell you that I liked the feeling, I had insurance anyway...)
So, fel is empty, BUT... anytime I went to pvp spots I found plenny ppl pvping(lots of ppl on Yew gate on the VvV). I personally dont like yew gate but you can surelly find ppl there if you want to fight and I believe in other citys too during the VvV system(didnt play it yet to see if this is true or not, just my guess)
I really LOVE the felucca ruleset(the only ruleset Ive played on UO all my life since 2000) I really don't enjoy the "security" that trammel brings to UO, IMO UO shouldnt have this kind of stuff: trammel and insurance (just wanted to say my opinion, I don't want to change the topic subject!!!
I like felucca so much that Im looting all my treasure maps there to run on felucca when I finish my treasure hunter(not only for the better rewards, I really enjoy there, the "look over thrill thing").
I really tried to play on SIege Perilous but the one character thing kills me... I don't want to afford two accounts right now to play UO since I can have more chars on Atlantic shard anyway, that has even more population and pvp going on...