My Rockwood (8280SS) would hit the cab on my F-150 Extended Cab w/SB, so I had a Reese 16K slider installed. I've only had to use the slider twice since I got the trailer in 2006 and I quickly learned that you do it on level ground!! 90° is needed very seldom, and with my Rockwoods original axles it put too much stress on the torsion axle swing arms and ruined one of them (after the warrantee expired of course).
I replaced the F-150 with a Dodge MegaCab 3500 SRW with a 6.5' bed, and have only slightly better turning clearance, so the slider's still there, just in case, but with a little planning I rarely need more than about 70°. The new axles I installed are MUCH stronger than the originals.
Hope the info helps.