i need to get a sliding bedcover for my 2011 f350 longbed,i have seen the add for paragon,seems pretty cheep,any body have one and how do you like it?any feedback on other brands would also be appreciated.

I don't know about sliding covers, but I have one called a Bak Flip that I really like. By far the best cover I have ever had.

fold-a-cover about the best out there...

I've been using these for years ( third truck) velcro, rollup, inexpensive, tough

http://www.agricover.com/

Do you like a soft cover or a hard cover?
I have purchased two Roll "N" Lock covers and installed some for others. I won't use anything else in a rolling cover. The Roll "N" Lock has several features and keeps everything dry.

I have a couple of fords and one still has a RolBak cover. It is very strong. Made of aluminum for the most part. Strong return spring, drain tubes several latching positions up and down the travel. The only issue with it over the years and I mean 8 or 10 years now is the rear latch point wore out and I had to make a new one. Took about a hour. Maybe they have beefed up that by now. Truckaddons had the best price and shipped it for free.

I have a Pace Edwards Rolltop on my Silverado, I'd give it 3 out of 5 stars. Its 2 years old, but the slides suck, and the lock is hard to actuate. Its made of aliminum, with vinyl overlay. The box it rolls into will take about 10 inches of your bed. It is not tough enough to stand on. It is a nice cover, just not very durable.

What you said is about what I found out when I was going for a Pace Edwards in the past. The cosmetics are nice but the product doesn't hold up well. I was going to get the power slider but the motors failed a lot too.

I looked at the Paragon cover. Seems like a simple cover and easy to operate. What happens if your boxes/load shifts forward to the front of the bed. Seems like you will not be able to open the cover as it folds down into the bed and nothing seems to prevent your load from going into that space.

Any thoughts on this?

I have the same cover, installed it in 2006 when I purchased my F25o Super Duty. It works great and would not go without one.