what's the difference btw, JSB Diablo Jumbo Exact RS 13.43 and the 14.35 Exact

Not sure? I have exact jumbo RS that are 13.43grains.

Really Small?? Lol.

Rally Sport! No idea! now I'm curious tho!

Rapid Speed because the velocity is greater than the regulat ones

hmm...(scratches head) aren't the RS 14.43 and hence heavier than the 14.35 std jumbo's? Wouldn't that make them slower? 

ah now that makes sense! 

I've shot both and will say the biggest difference I've noticed between the two is that the 13.43 shoots poorly out of the springers I tested it in, and actually often shoots a bit slower than the 14.35 as well as other, heavier pellets (counter intuitive, I know). Out of my Browning Leverage the 13.43 Averaged 741 FPS, with an Extreme Spread of 21.3 FPS. Out of the same gun, the 14.35 Averaged 747.1 FPS, and 16.18 ES, respectively. Not a huge difference in either set of numbers, but the 14.35 hits what I aim at, the 13.43 groups like a shotgun.
Similar (though more extreme) experience from a Benji Trail: 13.43 Average: 692 FPS, ES: 19.68. This compared to three heavier pellets (tho not JSB 14.35, couldn't find my results): CP 14.3 Brown Box- Av:743.4, ES: 20.57 and H&N FTT 14.66- Av: 724.9, ES: 26.14. Not exactly terrific numbers from the Trail, but it has a bad barrel. That said, the CPs, H&N, and JSB 14.35s all shot more accurately than the 13.43. Haven't bothered trying the 13.43 in a PCP, seemed like a waste of time to me. 

RS: Really Slow? Rarely Super? Repeatable Suck? I dunno...