It will pretty much come down to your opinion...what you want. Some searching on this forum will get you a whole lotta responses with just that info. Check it out.
Start with: What do you want?
That will include, how do you ride, where do you ride, what do you need your bike to do.
A couple of things to keep in mind.......
The pipe of choice from anyone is just that...their choice. Maybe it won't suit you.
A 200 isn't at all the same as a 220 (yep..it's true!!;) ). You have a 220. Consider that a 220 comes oem with a 33mm carb, the 200 with a 35mm. Beside the larger bore being a pertinent issue, the port timing between the two bikes is NOT the same. The 220 has a better bottom-end than the 200, but it doesn't have the top-end of the 200.
If you want more on the bottom (and your choice is the FmF pipe), then the -35 (torque) is your choice.
If you want more on the top, then the -30 (rev) is your choice.
...but that's just about the pipe.
A 36mm carb on your 220 would improve the top end (still not to the level of the 200 due to the timing issue). With that PLUS a -35 pipe on your 220 to add to the existing good bottom-end you would get a boost on both sides!
Stuff like that. It matters what the pipe is combined with..and where you need your bike to work best.
If your riding is in 4-5&6 gear..then get a -30 (rev). If you're in 1-2&3 more of the time...then a -35 (torque) would probably be a better choice.
BTW...the -35 is a WHOLE lot smaller pipe than the -30. Probably not something to consider under purchasing do's and don'ts, but the -30 sticks out there purty good!
The PC pipe is closer to the -30 than it is to the -35.
Watch all the bogus adjectives...desert-mountain-burly-gnarly etc etc. You have exactly TWO choices when it comes to FmF and the kdx: -30 and -35. They both have the same type effect on the two kdxs. I've seen catalogs that list only the -30 for the 220...and call it a torque pipe to boot!!
PooP! Isn't true. Just the two. -30 for the top, -35 for the bottom.
Gee....guess I've beat that pretty much to death, 'eh?
Good luck!