Hi Nordic,
Happy New Year to all. I have a Honda BF8 kicker on my 22 Classic. It brought me home once when the impeller failed on my BF75 out in Galveston Bay (curiously, the day before I was wondering in my head if it was time to replace the water pump impeller on the BF75 and obviously the answer was yes). So even though I had to cruise back to my marina at 5 knots. I avoided the embarassment of returning via SeaTow or TowBoats US. It also brought me back once when I couldn't get the big motor started due to a self-inflicted electrical problem (make sure those battery post terminals are really clean and tight).
I like having a kicker for the peace of mind of a backup motor, and a backup alternator (see battery posts). One time my battery (OK, I admit I've only got one) was too low to start the big motor after sitting unused a bit too long. Hey, rope start the kicker, and you've got an onboard battery charger. The downsides are additional initial cost (which would buy a bunch of tow insurance), weight, and additional maintenance. I try to run mine every time I use the boat to make sure it is in good shape if I need it, and I maintain it on the same schedule as my big motor even though it sees about a tenth as much use. I've heard several stories of folks who had a rarely used kicker which failed when they really needed it.
There are several previous threads discussing sizes and models. Hope that helps!
Mike