I also had that question of choosing between a red 637 diode ( less mW and more expensive)... or a 650 diode in my H-RGB1800 from goldenstarlaser.
The laser i got are fro laserwave, not CNI. They are really compact!! and all deliver more power than their specs say.
I am 100% satisfied with the decision of choosing the 637 diode with round beam. The divergeance make a huge difference in the display show. the red look more clean and is really bright for a 170mW and dont forget it is matched with a 670mW green and a 1W blue!!.. as well i still need to add more power of red and i'll do but actually it is satisfying me enough so i can wait until i have the money to get another quality 637 laser from laser wave.
Doc
Pangoline Quickshow FB3
H-RGB1800 with DT40 and Laserwave OEM pro S modules (r637nm 190mWg532nm 710mWb447nm 850mW)
Old set of G120 scanners and one Cambridge 6850
1.4W 445 blue pointer