Some subjective (As in what I like) pros to mainly play on lazer client over stable:
1. Easier HUD customisation. Previously on stable, you have to use skin folders, know how to edit skin elements yourself, etc. Now on lazer, you have easier option to simply move and resize skin elements
2. No Notelock. I personally don't mind notelock but I'm aware a huge portion of players do, so there you go
3. Easier to pass hard maps. If you're more of a pass player rather than consistency, lazer might benefit you
4. Your mileage will vary, but the lazer performance is better on my laptop than on stable
I think you can try both and play it side by side, decide it for yourself. If you have some specific problems persist on lazer (poor performance, lag spikes, weird aiming, consistency issue, simply can't get used to it, etc) then I suggest to hold back a bit for future updates