As you can easily see when you visit LessWrong.com, the site transfer is complete, and we are now on the new URL. The data import will run for the next few hours, and by tomorrow morning everything should be complete.
Let us know if you run into any problems, find any broken links, or anything of that sort!
Personally, I think the greaterwrong site (or rather, something functionally equivalent to it) should be the main or only way LW2 is accessed via the web. The technical solutions found in Lesser Wrong (including Meteor and Vulcan) may be appropriate in an actual PWA (Progressive Web App, basically a bunch of JS and 'style/formatting templates' that get installed on your device/computer as a proper, well-defined application and then interact with the remote site via a web-based API of some sort) but they have no advantages to speak of in a traditional website.
We are pretty close to being a proper Progressive Web App, and I definitely see this as the long-term goal of our current design.
There is no reason to reload the whole LW application on every visit, but with Application Storage being phased out as a web-technology, and Service Workers not yet being fully available on Safari and Edge, there isn't yet a great way to give everyone a good experience with a progressive web app. But I expect this will change within the coming year, with safari and iOS support being in the late stages of the beta. So there is a reason behind the design choices we are making.