The system is an HP notebook and as far as I know, there's no crapware running. I haven't looked to closely at this yet though.

I searched Google and a lot of other people complain about slow explorer copying.

It seems that sometimes grabbing less files will allow the copy to move faster. ie. 25MB/s instead of the 100KB to 4MB/s that I've been calling "slow." Usually it won't go faster than 1MB/s though.