Wheels are really easy to get used to if you're are the only one putting the tickets up. You use pretty much out the same system as with the rail, always putting the tickets in the same order etc. It helps if you put a reference mark or number the slots so you can keep everything straight.
If you have the waiters posting the tickets on the wheel, it can get a little confusing. Common problems include putting tickets in the wrong order, and waiters not turning the wheel back after they put the ticket up.
Imagine if you will...
During the lunch rush, you take a glance at the wheel, its on tickets 5-8. One of the servers posts a ticket and doesn't turn it back. You take another glance to check that special order, and the wheel is on tickets 19-23.
Personally I prefer the rail, since I can see everything at once.
One thing I can't figure out though, is how you can have room for a ticket wheel, but not have room for a ticket rail or a check minder. Most place's I've worked had them bolted over the pass, to the lip of the pass shelf, or over the cold tables for the station.