If you're used to regular rubber domes you'll most likely have no problem with blacks.
The first mechanical keys I came across were blacks, at a time when I used a regular rubber dome at home, and I didn't think they were heavy at all.
After a while with mechanical boards, on the other hand, the blacks feel heavy every time I try them (I have a board with blacks I can't actually use with my computer) so I ended up with a QFR with reds as the latest addition to my collection.
On the other hand; I have a friend who went from rubberdomes to blacks and he doesn't think they're heavy at all, even after months of use.
I'd say blacks could be a safer choice than reds, although this is a fairly subjective thing.
In this situation though; I'd say the QFR as the lack of numpad gives you a much more comfortable arm position for both arms, which is really nice when playing FPS games.
In summary; they're both linear switches and the benefit of not having a numpad is greater than the difference between switches, at least for someone coming from domes.
