I just asked that question and answered it for myself about 3 months ago. I had a v1 from pre v2 days. I will say this, unless you are looking to add a lot of Osram bulbs I say there is ZERO reason to migrate to v2. The zigbee firmware updates to devices is a nice perk. But none of my sensors had any issues that I would attribute to zigbee issues. I still have the Cree ‘bug’ where the firmware sucks and drops messages. They havent pushed any firmware updates for them yet. The osram’s got the fix and everyone says they are fine.
So the process of migrating SUCKS. I do have a lot of things but still yet that isnt even half the problem. Losing all your automations suck. I spent a day taking screen shots of everything and I think I missed some. Then one thing I didnt think of… I am now on shard 4 (na04) instead of the original shard. You would think they wouldnt be different, and as an ops type of guy the benefits of keeping systems the same is huge. But I’ve seen more issues that I would attribute to the na04 shard than anything else. People would complain of issues and I wasnt affected at all, now I am.
First few weeks I was doing nothing but cursing my decision. There was zero noticeable benefit to the change. Now a couple months later I’ve ironed out most my issues. But still I couldnt tell you there was any difference in my day to day use that is improved by going v2.
If you are stable and happy…and not adding a bunch of Osram bulbs, I vote dont change. Until something changes with local processing theres no benefit. I am running a very ‘stock’ setup by using ‘stock’ dth’s and just smart lighting for my automations… I have only 2 automations out of about 25 or so, that run locally. Part of that is my use of Hue, but still even with the Cree bulbs they dont qualify for local processing.
Unless you just want to mess up a solid weekend, and cause havoc for a week…dont bother.