Anyway, I used maczfs for years until it hit a point where I couldn't upgrade os versions anymore so I switched to O3X. I don't remember when now but it's been a few years (I think around when spotlight support was added?)
Out of general paranoia I have not upgraded the pool. I just moved to sierra last week and 1.6.1 worked without any hitches after the upgrade, even though I forgot to export the pool beforehand. (This freaked me out during the last upgrade when the pool wouldn't show up at first

Anyway, I'm finally sort of ready to upgrade the pool, primarily to get access to zil/cache SSD drives to help performance (the 4tb drives I have are slow green drives and can be somewhat painful) and a couple other features. If it makes any difference the pool is almost full (in fact I had to struggle to delete some things a couple years ago when it accidentally got filled up and didn't act very nicely...)
I'm wondering if there are best practices for doing the upgrade?
I've thought about just doing it and hoping

Are there any tests, etc I should run first?
Has anyone tested upgrading from pool version 8 before (I assume so) or recently (maybe not)?
thanks