We've announced that r100 will support exporting to iOS and Android via appMobi directCanvas and Ludei's CocoonJS - and both are currently available in experimental form in the current beta release. Have you tried them? They should bring native-like performance to your games. We do not currently recommend using the device browser or PhoneGap on mobile for the time being, because performance is usually poor (except Safari on iOS 5+ is actually pretty good, although PhoneGap makes it slow again), so those two options are the only ones you should consider for the time being. Considering we've also spent a lot of time optimising our engine, I think it will be highly competitive with native engines.
We already support exporting to Windows 8 Metro apps as well, has anyone tried it? This means we will be ready as soon as Windows 8 tablet and phone devices start shipping, and when Windows 8 for desktop is released too.
Apart from that, I'm not really reading any specific concerns in this thread. If anyone can point out any specific issues where they feel Construct 2 is falling behind, let me know and I can address them. I'm sure in the near future Construct 2 will be a great way to make mobile games so hopefully describing some of our future plans will help put some of the worry to rest.