I've switched to Cocoon with Canvas+ for a few months now and I don't miss Intel XDK. I'm just doing the finishing touches on my banner and interstitials and for now they seem to work fine using the CocoonAds plugin. I've only tried AdMob and Android so far. I hope the in-app purchases will go as smoothly with the Cocoon plugins because I'll be implementing them next.
As far as performance is concerned, Canvas+ is really the only difference between XDK and Cocoon and it has it's tricks. You must not use regular vectorial text with Canvas+ as that will severely impact performance so you have to switch your text for sprite fonts. Also some Browser object commands may not work with it, like exit app for example, but that's no problem because they provide you with the CocoonCanvas plugin that can do that among other things. One downside of Cocoon I can think of is that you have a splash screen that's very expensive to get rid of and depending on game size there may be a black screen gap of a few seconds between splash screens (you can also ad a custom one in addition to the Cocoon screen) and your loaded first layout. Supposedly using a loader layout should fix this but it doesn't. It may just be a bug and fixed in the future.
One other thing you should know if you're used to developing for PC and want to expand to mobile is that WebGL effects should be used carefully because some phones, for some reason choke hard on these effects. I couldn't tell which exactly but I know that with WebGL effects my game was running at 5fps on a brand new HTC octocore and under 30 fps on my 2 year old samsung with 4 cores... To be safe I removed all WebGL effects and all of a sudden it was running at 60 fps on anything. It even managed a steady 30 fps on my old Huawei dual core with 512 ram. So if you must use effects, try to test each one on as many devices as you can before you implement it.
I think if you go with Cocoon you will probably have less headaches than with Intel. If you choose Canvas as well the number of bumps in the road will increase a bit but it should be well worth it because the performance is clearly above Webview, especially if you're making games that require reaction speed and agility. Oh yeah, and Canvas+ also means a smaller app package because it's wrapper is about 10mb smaller than Webview.