I'm one of those who didn't get much relief from tramadol ER, but I get good relief for 4-5 hours from the regular one. I've gone back to the regular version. The only thing is to take it at the same times each day and not wait until you are in pain because it takes 45 minutes or so for it to start working.
I don't take tramadol at night because it keeps me awake. It's great for getting up and going in the morning.