I learned to ride before I was 5 - without training wheels - and never regretted it. I had the seat low so that I could scoot but I don't think that lasted too long; it's just too much fun to coast. Dad held on a little as well but when he could let go and I could get around, we put the seat up a bit. Kept doing that until the seat was right and I've never looked back. Well, except for that time when I cornered with the inside pedal down and ended up with part of the street embedded in my leg. It's still there now, 20 years later!.
Four years after I learned to ride I watched Dad teach my sister. He used the same technique and again it worked fine. No training wheels needed.
The only thing I might change when I teach my kids to ride in a few of years (number one is turning two today) is I might remove the pedals. They did get in the way a bit.
I think the important thing is to take it slow though. Just do a little each day and put the bike away. They will soon learn to look forward to it. If you push it for too long, they will resent it.
Have fun!