They are very difficult, which can make for a nice challenge.
I just had a 1 on 1 match in silvercity with only laser guided rockets for the first time. It took a while to figure out how altfire and regular fire interact with each other, but after you know, you can get quite strategic.
They did make for a long match on the large map which was definately a change of pace, and its hard to gain and hold a substantial lead.
Overall, they're fun, but definately not competition type stuff.