Since I saw this topic I decided to try it out again (after downloading the november build yesterday) and it seems that some of what you say may have been fixed.
Edge uses almost the same amount of RAM or less or more when compared to Chrome (same tabs running). (Checked again, youtube consumes ~20% more on Edge (340 MB vs 405 MB) Not a problem for me though, I don't have a potato PC.

I have yet to come across any lagging on Edge (even when on the 10240 build, I REALLY had no lagging on Edge ever since I started using it). In the november build, there's still no lagging either.
On the pre november build, it did get unresponsive at times but so far it seems perfectly fine on the november update.
And yeah, I am posting this on Edge, I don't see any problem with the formatting or anything. Works exactly like it should on Chrome.
And the 2012 hating on MS IE is getting really old and boring, Edge is nothing like IE (in this build). It's smooth, has all the features I need (addons/plugins doesn't bother me cause I don't use any). LOOKS simple and good.
MS didn't pay me for this.