I think there is a long way to go on this as you'll find many SL merchants don't even like the default "full perm = exportable" paradigm that viewers currently enable for all opensim grids.
From a consumer centric standpoint obviously a multi-grid market is a good thing, but from the merchant standpoint, some of them actually enjoy being able to sell on and to multiple grids and make extra by reselling the same items on each individual grid. Why is this? Because they end up having to go to and support the items on each grid anyways (especially stuff with "moving parts" so to speak, scripts, etc). Selling it once and having it be able to go to a bunch of grids means a single sale, single point of income, but multiple points of support.
Even grids running the exact same code won't have exact same behaviors due to their different backend setups.
As far as innovation, game changing etc, without actually actively working at increasing the number of participants in the current alternative/free metaverse, none of this is going to mean much.
As far as the other points about closed/open/catchup etc, I think we're well beyond that kind of talk now. I really don't need to start comparing feature/functionality sets again, as it is not a winning argument for either side, and only serves to further divide the already small number of metaverse participants. (internet relative terms of course)