Your swingarm will still have a '200' sticker on it...right? Doesn't that mean it's a 200? ;)
As long as you're asking for opinions...I'll give you one. I had my cylinder bored/replated due to a coating tear. Figured, 'What a great time to have it ported!' And so I did.
I asked that the bottom end not be negatively effected..and I wanted to continue to run pump gas (92 avg. octane hereabouts).
While the motor does run better...it's not a huge difference. What is different? I cannot get rid of the pinging I have now without running at least a mix of pump gas/race fuel (Trick 114). The bike rips on top with that mix...but the loss of bottom end response is plain unacceptable. It pings considerably less now than it did when I first put the cylinder on. That is due to an RB-Designs head reconfiguration. If I'm on a hot toot..maybe chasing a CRF250X for example...I hear a good number of marbles rattling around. He doesn't usually get very far ahead of me, though! A better rider would pass him, I'm sure. ;)
Another thing that is frustrating: I've been up, down and every way back and forth on jetting the ported cylinder. Haven't gotten it right yet. Probably won't. The bike used to have an S/A spout that was dry as a bone..no flick of spit ever, nowhere. Ran great! With the ported cylinder I've never gotten rid of having at least some spoo.
If I could change back to an unported cylinder with a simple push of the 'Easy' button...I'd do it. I'd keep the modified head, though.
Why a Wiseco? The 200 Pro-X doesn't have any problems. Wiseco's have had problems.
Maybe you'll get lucky.