4/5
I've never really used any other Thermogenics except OxyElite Pro... But I can say I loved FatSmackXr. I'm still running it. The extended energy release is awesome. I'm never jittery but I always seem to have energy even with a carb deficent diet. I'd say two caps is a good morning boost instead of coffee and one a few hours later will ensure you good energy.
Also, the heat factor is awesome! I never sweat in the gym like I do when I'm taking FatSmack. I've actually asked some guys in the gym "is it really hot in here today" when I first started taking it...
All in all, I'd say it's a great product but it's all about diet when it comes to cutting. However, FSxr will give you that extra boost for sure.