What's the impact of blade RPM on a table saw?

Higher RPMs will also make better cuts, and extend the blade life, if the commercial cutting industry is to be believed. Many commercial lumberyards like to run their cutters between 10,000 and 18,000 surface feet per minute (SFPM). 18,000 would be a maximum ceiling, so they often aim for 15,000 SFPM.

Diameter * Pi * RPM / 12 = SFPM

At 10 inches and 5000 RPM we get something like 13,000 SFPM. At 3400 RPM we get 8900 SFPM, which might be too slow for most materials.

I'm not sure how this would affect blade life and cut quality in the home shop, but I'd assume a modest amount at or over 10,000 SPFM is what you want.

Now, these SFPMs might be about maximizing speeds and feeds, and it's not like lower RPMs are going to ruin anything as long as we reach a minimum. Almost certainly the SFPMs back in the water- or stream-driven days were lower. But there is definitely a sweet spot, which certainly drove the need for larger diameter blades.

But these are the typical SFPMs for carbide cutters. At the end of the day the max RPM at 10in is probably not the deciding factor for a new table saw. Things like build quality, motor quality, drive train reliability, and (most of all, at least for me) quality of the fences and guards. I'd take a lower RPM, better built, more easily serviced, and with a good selection of guides and jigs (or easy to adapt for home made guides and jigs) model over something that screams faster.

It's not like we should be in that much of a hurry.