I use a Swivel Wheel. You can see weight calculations at their website. Course, if you already have a hitch, you may not want to fork over the extra money needed for the swivel wheel receiver set up.
But being able to back up easily does have it's advantages.
2013 F350 6.7 DRW SC Lariat
2011 Brookstone 354TS
Swivelwheel 58DW
1993 GL1500SE
Yamaha 3000ISEB