I started with the Moon ACE, then upgraded to the 340i/280D combo. It was an improvement over the ACE. Then I demo'd the 700i v2 and it was even better! It's difficult to imagine how much better until you hear it. So much so I traded up the 340i for the 700i v2 and the 280D for the 780D. If you like the idea and convenience of an integrated the 700i v2 is a great way to go and it sounds better, I'm told as I didn't compare them personally, than the 600i v2. You also get more power. Coincidentally, both are available used on The Music Room site at a fraction the cost of new.
I've read the posts and those who have owned 340i and I agree there may be other things to consider: setting your speakersroom and cables. I have KEF Reference One Metas and they image quite well. Previously with the ACE and 340i, I had the LS50 Black Edition (non-Meta) on the KEF S2 stands and they also imaged incredibly well.
I hope you're able to gleen some benefit from my ramblings here and I wish you the best in your pursuit--this hobby is like an diving into a fractal.