the 26" ripper is alloy, om flyer is cr-mo.....26" ripper is a bit lighter, 2 pounds, 26" ripper has a half inch longer chain stay, other than that the geometry is identical. hence the frame shape is basically the same between the 2, you can get all the specs and geometry on the se website....
all of them, except the om flyer , have floval tubing too...
would expect very little difference between the ride of the om flyer and the 26" ripper bearing in mind the geometry is almost identical bar 1/2" length of the chainstays, the cr-mo frame should give a slightly less harsh feel, but when you're running 2" tyres, its unlikely this would be particularly noticable.
i really like my 26" ripper as a commuting type bike and its alright for a blast at the track, certainly unlike my new school floval on the track though, but thats a completely different type of machine and that isn't very good for just general transport/riding about as its much smaller (10" seat tube/24" wheels vs 15" seat tube/26" wheel) and has much sharper handling.
not ridden a big ripper (29") but do have a 29 mtb, and think the wheels would be a tad large on a bmx.....they definitely are less agile than a 26, but if you want a bike for transport purposes, do you really think a single speed, bmx is the best option?