What discs fit the DeWalt 908?

It takes 4.5-inch discs with an M14 threaded centre, the most common size for this class of grinder. Both cutting and grinding discs in that size are widely available.

Is it better than a cordless angle grinder?

For long, heavy grinding the corded 908 gives constant power with no battery changes. A cordless 4.5-inch grinder is easier to carry to remote work but costs more and runs for limited time per charge.

Does it have a brake or variable speed?

No. The 908 has a single fixed speed up to 12,000 rpm and no electronic brake, so the disc coasts to a stop after you release the switch.

It weighs about 5.2 lb, which is on the heavier side for a 4.5-inch grinder. The anti-vibration handle helps, but expect fatigue in overhead work.

What comes in the box?

The grinder ships with an anti-vibration side handle. Discs, a wrench and a case are not included, so budget for those separately.

Is it good for a first-time grinder user?

It is powerful and simple, which suits learning on flat work. The lack of a brake and its weight make it less forgiving than lighter grinders with soft-start, so practice on scrap metal first.