I use a serger on all of my fleece items. It's so much faster! Just be sure to test the tension on some practice fleece, especially if you've switched from a different fabric. Fleece also tends to build up (as fluffy dust), so be sure to have compressed air to blow it clean now and then.
I haven't had any issues with the blade becoming dull. I suppose it's possible, but even after a few years of sewing fleece, I haven't had to change any blades.