Neobux is better in terms of click rates and the simplicity of the PTC ads. I like this site better than the other one. Palmbux isn't as simplified as Neobux. I don't like having to wait for another system to click after checking out the ads. It requires more time than Neobux but lesser click rate. Payout rate is just $2.00.
Joining these sites won't mean you'll get big money from doing PTC ads. It's just a few cent/s and it will take time before it becomes a dollar at least. The better way to earn from this is through referrals. If I don't have any works to handle I don't really mind doing the PTC even if the rate value is very small increment. In time without knowing it you'll have few bucks already.