I know they're not as popular but I do still see them. Or 660, for those who want a more true red. My old one used a 641. As far as modulation goes it's just all about the quality of how it was made. Though I will agree that bare diode is better in that department, and opsl is better even still. In fact up OPSL modulation is so clean it's incredible.
For 100mW or so:
671 is not that expensive. last time I built a good one it was about $350 for the green 532nm, $600 for a 671 and, and about $700 ish for a 473. The beams were much nicer than what I've gotten with diodes because they were circular and Gaussian, not elliptical and a top-hat profile. When it comes to modulation of DPSS it really just depends on how they decided to build it. Not all lasers keep their temperature management while they're in the 'off' state. You need one with temp controls even when not active.
I have done all diode builds (462/520/641) and they definitely beat them out in power unless you want to pay out the nose. Diodes are cheaper too, but don't mix as nicely.
And then if you want to get into the ultra clean stuff, you can get OPSLs, but the cost is absurd. (460/532/660) usually, tho really you can mix and match however you like now. They have nearly everything.