A convertible jacket works when the conditions change enough during the ride that makes it worthwhile to remove the sleeves -- like when it'll start out cold but warm up during the ride. I use one for commuting where I'll have the sleeves on during the colder ride and the sleeves off on the warmer ride.

It's nice to have a two in one piece, but the convertible jacket I have and most others I've seen are too loose fitting for my preference on recreational rides. On recreational rides, I prefer a tight vest and arm warmers if it's not too cold, but use a tight jacket when it's a colder day.