I've had the BackFlip on my truck since July 2014 and while I love the look, I would not buy another one for the following reasons.
My biggest pet peeve is it is difficult to roll up and down once the outside temperature drops to 30 degrees, the colder it is outside, the more difficult it is to roll up - and down, once it gets below about 10 degrees, forget it, it is impossible to roll up. I have not actually tried to force it to roll up when it's that cold out because I feel sure I will break something. For me, this is a deal breaker.
When it's warm out, it rolls up with one hand smooth and easy though.
Next, while I knew that it is not waterproof, it leaked only very slightly at first, no big deal for me - but almost two years later and it leaks pretty bad. I think the main reason is when the cover is rolled up and secured with the straps, the straps themselves pull the front corners of the cover up and away from the bed, effectively unsealing it from the bed even after it is rolled back down.