Re: Question for jackshaft guys?
I don't own one myself but have installed 2 for others and tried them out. IMO the eninge is much easier to start and also easier to get the bike going. There was no adjustment to original chain/sprocket required and both these setups are working great. I really don't think you need special wheels if you've been offroad pedalling. Unlike what many believe though it does not improve top speed compared to using a small sprocket.
Personally this is not for me though because I go on long trips and the redundancy of two drive systems is essential. Something you sacrifice with the jackshaft. Kinda like with the clamshell hub sprocket mount kits, sounds like a neat idea at first until you need to switch bikes. There's drawbacks. As Roseanne Roseannedan says: "It's always sumpin'!".