In my opinion, the spud inc. deadlift belts are shit. No matter how tight I got the damn thing, it just never gave me the support and stiff feel that I like. I also REALLY hate that the belt is not of a uniform width. Where the velcro part gets cinched in there is a noticeable lack of abdnominal support in the front due to its tapporing. In general the thing just had way to much give everywhere.
I have the inzer 13mm lever belt and could not be happier with it. Getting the belt tight is easy as pie, as I don't have to pin one end of it against a power rack or some other immobile object or have 1 or 2 other dudes help me tighten it. Its also very stiff, a uniform width and gives plenty of support.
The only warning I will give for it is that when you first get it, you will be tempted to place the lever at the tightest setting humanly possible. I did this, and while it gave me an incredible amount of support, and it sliced into me rather well. Even managed a bloody undershirt from it. I found this out because I was used to those really thin crappy belts that required rookie hooker type tightness to provide support. Lesson learned.
OP, I tried the spud inc. deadlift belt, and felt it to be nothing but a waste of money and ended up buying the inzer lever belt anyway. I can't really comment on the 10mm belt as I have never used it, but if its anything like the 13mm it will serve you well.
If you prefer prongs, a buddy of mine has the APT 2 prong 13mm belt, and it works very well for him. The only real difference I have noticed between the lever belts and the prong belts(provided that they both are the same thickness) is the ease with which the lever belt can be put in place and removed. Both have the ability to pinch your skin if you don't get them set up just right, though only the prong belts have done this to me during a lift. The lever belt never has.
I have a few vids of me using the lever belt in my profile, and I have never had a problem getting into position for a deadlift, even from a defecit.
Hope my rant was helpfull.