My opinion is that one should perhaps not increase the max-swing speed, but make the str-builds slightly slower, as it is a no-brainer to go for a lot of STR nowadays. Even I got 18, and don't really suffer from it.
I understand that pre-nerf my lvl40 with about 210wpf, 30 agi, 10 Athletics and 6pthrow might have been a tad OP.. :-)
Giving a slight slight nerf to choosing STR in swing speed, and giving Athletics some of its puff back would be nice. Not by a lot of course, it's almost perfect now.