They work quite well, but the added weight out front makes shooting offhand more difficult.
If all things are considered, you would be just as well off, probably better, by choosing a conventional scope of low power, such as the Leupold 2x7-33. And I offer that advice as a big fan of the Scout scope system. Just not on my Arf.
Picture of my A2/SPR(Scout Practical Rifle) from last summer.
I was on heavy pain meds at the time is really the only defense I have for making it...although it DID shoot a 0.75 wide x 1.75 tall five shot group at 200 yards! As mentioned above, for the same weight, you can run the 2x7 instead of the Scout 2.5X(Leupold) or 2.75X(Burris), and the rearward mounted scope will balance/handle MUCH better.
Paladin
ETA: the weight of the 2.5X Leupold(upper) and pair of rings is only about 12.75 ounces added to the fairly heavy 7.62 Scout. the RRA scope mount shown(lower) weighs 10.75 ounces WITHOUT the scope, add in the scope and an HBAR and the weight distribution really SUX compared to the 7.62 Scout.