Okay, so I've read all the pros and cons of child seats and trailers, but still feel happier with a seat rather trailer. What I would like to know though is which seats people recommend. I think I've narrowed it down to three or four, but maybe there are others worth considering. They are:
Hamax sleepy (deluxe?)
Co-pilot limo (forced to buy a blackburn rack, which all my bikes have anyway, so I don't need another one)
Topeak Babysitter (this time you need their special rack - see above)
Kettler Flipper (from what I could find out it weighs a lot - 6.8 kg! according to one site I found)
I bought the Co-Pilot limo and both my 15 month old daughter and I love it. My daughter is on the tall side (I'm 5'10 and my wife is 6'1) so the adjustable footrests don't do much for us, but it is nice to have if we have another child that's not as tall. The seat attaches and detaches relatively easily and when it's off it can be used as a child seat (the safety bar locks in a backward position and provides support). It's also pretty light...
I have no practical experience with the others you mentioned but I did see the Topeak in a LBS and liked the Limo's saftey bar better than the Topeak. The Topeak bar swings open and the Limo swings up, to me it makes more sense to go up since i park my bike very close to a wall...
I'm just over 6'2", but my wife is only 5'4" and at the moment Alex is slightly below average for his age at the moment. However, who can tell what he'll end up like, as I was 5'4" at 16 years old and 6'2" and 18! I appreciate your comments about the Co-Pilot limo and Topeak seats; if i could find somewhere I could get a limo without having to buy another Blackburn rack that would even better.
I've installed several Topeak Babysitters for customers and have found (in my opinion) them to be better engineered than the Co-Pilot. I'd certainly put my (hypothetical) kid in a Topeak before a Co-Pilot given the choice.