im currently a zolazin saboteur and i was thinking about going Kronyn since i have lots of massive but VA planets im rank 222.
so what do you guys think would be best

Research isn't really all that important at higher levels but you can sell them for a nice profit.
Sabouteurs are great for legions, and helping out fellow legionmates.
So I'd say it depends on your style - teamplayer or not.

I'd stay as a sab - Research loses it's value fast, and a good legion base can compensate for it.

Your choice - help yourself get a little more research, or help you AND your legion get a LOT more of everything by increasing the chances of taking nice planets.

Zolazin Sab. Kronyn is at most, +100/hour each week with the best modules with a good set-up. Not so worthwhile, I think.

Zolazin sab can get you amazing planets, that would take months to make from Kronyn.

I was Kronyn for a long time, cuz my research sucked. But I'm telling you, stick to Sab, and join a great legion that wants/needs sabs. You have no idea the kind of planets that will be thrown at you.

Ok, now I haven't been a sab, nor do I ever plan to be, but I was Kronyn for about 4.5 months. Here's my take on this decision.

(1) Low-ish rank means a lot more stuff yet to be researched.
(2) Single sabs don't help you get "amazing" planets. They are rarely, if ever, around with a clear timer when you need them. And most of the amazing planets are filled with structures that you can't sabotage anyway.
(3) The Rangers, correct me if I'm wrong, is an artifact base.
(4) If you pay attention to what you are doing, you can easily get more than "+100/hr per week." I have a VM UR Gas making 247 rph with 8000 invasion defense and less than 500 cloak. I also have a Col 17x Plasma making 840 rph with 19k invasion defense and over 1500 cloak. To go from UR to 15x takes 26 days 16 hours (less than 4 weeks). Plasmacize it, and you have an increase of nearly 600 rph.
(5) For me, knocking out an Obviation Barrier (best case) gives me an extra 3-5% chance on invasion with the 3 basic attack buffs. Wow...

A few things to add; The arti's along the Kronyn mission are useful, sabs are helpful to legionmates, but how about giving plasmas to legion mates? I think thats more helpful. Selling or trading Plasma for Arti planets, You can balance out your gaia planets you are using terraformers on, Allows you to be in an arti legion...and everyone knows artifacts=win, Research becomes credits late in game... shall i go on. Let the naysayers say Kronyn isnt good, i say enjoy the advantages until you go Taltherian.

1 Obviator grid is still enough to put my chances WAY up. Sab and Kronyn are both for lowbies tbh.

I've been wrestling with the same decision. Maybe some of my thought processes will help you - or vice versa!
I am currently a Zolazin Sab and have been for maybe 80 ranks now. Before that I was Inergon (and before that, Human).

At the time I switched to Zolazin, it was a choice between that and Kronyn. My reasoning was that Zolazin Sab would allow me to take some planets I couldn't otherwise take, whereas Kronyn would help me to boost the planets I already had. It made more sense to me to go Sab first and use that to take planets; and then later on switch to Kronyn. That is still my plan.

There have been a few shiny planets that I have been able to help legionmates capture. There have also been a number of planets I sabotaged for myself because it brought the defenses down to a range where I had a decent chance of taking the planet (with the attack I have, losing one Planetary Shield or Obviation Barrier makes a *big* difference!). And I recently took two days to bulldoze the defenses on an inactive world so that I could have an easy takeover. There's no question that it's been useful having the Sabotage ability.

However, I am also getting to a point where I *really* need more research because I'm getting to the expensive end of the research trees. Yes, research will eventually cease to be useful; but that is long-term (double my current rank, probably). In the short-term (next 100-200 ranks), I need a lot more research than I currently produce. That is the main reason I am thinking to switch to Kronyn.

The other fact is this: while there are days when being a Sab is ridiculously useful, there are many more days when the ability is not needed. Maybe it's different in your legion; but in mine the demand for Sabs has not been so high that I think changing race would cause difficulty. Otherwise I would not be likely to change any time soon.

I'm still plodding my way through the Kronyn chain, and things might change before I finish it, but that's where I stand at the moment.