I think Bill C summed it all up pretty well. Most new 5th wheels are designed to be "short bed friendly". Meaning they give you much better rear window collision avoidance than previously. But with that also comes the word of warning that even the best of designs can't account for all circumstances. You will need to check with the dealer or manufacturer to be sure of the clearance for that specific model.
If you are set on getting a short bed (or standard, or however it is referred to), I would be safe and get the slider hitch. Even if you find you don't need it for most of your experiences, there may be that one time you wish you had it!
For the record, I had a short bed F-250, then went to a long bed, and am now back to a short bed. The long bed was a bit daunting at first, but once I got used to it, it was really not that big a deal. I already had a slider hitch from the first short bed, and I never used the slider. We'll see how it goes with the new truck.
Ed and Sharon
2010 Wildcat 28RKBS
2011 Ford F-250 XLT, 6.7L PSD
Ride-Rite Airbags and Airlift wireless remote compressor...nice!
I thought I was wrong once, but I was wrong!