best solar panel, bang for buck & durability

Hi Steve,
Mine are mounted at a slight angle, but only so they clear other stuff packed on the roof rack. If I'm not using the roof rack then they mount on pack bar mounts and sit flat.
So I tend to agree with you; esp if the glass/coating is stippled, which takes the sun in from a wider angle, it's better to mount them flat, and accept a small reduction in performance for total convenience.
But there is still an improvement facing the panels directly to the sun, and mine can tilt for those days when there is minimal sun due to cloud.
I agree, the Unisolar are pretty unbreakable, just a bit bigger for the output than the crystalline versions. A colleague had them - I advised him to tie them down securely to his roof rack. He used occy straps to tie them down, and of course the wind blew them up and bent them. And someone drove over one corner, and they still kept working. They still worked fine after these mishaps, so they're fairly indestructable.
The Unisolar seemed to be less temperature-affected than the crystalline versions as well.
I've seen a comment somewhere that the soft plastic coating on the Unisolar can attract/absorb dust to their detriment. Perhaps you could comment on this.
Cheers
Gerry