This is highly opinionated, and is my opinion. Let me start by saying I've been running a personally customized version of 1.9.7 since shortly after it came out. These are sites that have been upgraded and were initially installed as 1.6ST. I have two 1.10rc test sites that I use on a fairly regular basis these are clones of my production sites that I upgraded. (to test things, to be able to answer questions, for developing the mods that I have authored, to test upgrading, etc.)I look at the forums here on average 5 days a week. I read every post.I look at the issue reports at github. I read every issue reported.We usually run a few versions behind here on production just because I feel like its more stable to do so.My perception is that 1.9.12 and 1.10rc2 have a lot of problems. If I remember correctly 1.9.8 is when they (the devs) also started moving talking to the database to ORM. While I think that in the long run this is a good and positive move, I personally am not the best coder and have a hard time wrapping my head around how to code using their ORM structure. I imagine that if I did it with any real regularity I would know it by now ... I also like having the old SQL queries to be able to tweak, toy with, etc. So I feel like being against the transition would just be me being a curmudgeon. The benefits of eventual additional DB support, performance, etc seem in my opinion to really outweigh me wanting to be able to hack the thing. :)Feature wise I'm really looking forward to 1.10.0 and cannot wait until it is released. I had a lot of problems getting it working in my environment (IIS8.5) initially but that's what my test sites were for. I've manually installed a bunch of the post 1.10 fixes on github and am mostly happy with it's reliability. We plan on upgrading to 1.10 once it is released (okay so we'll probably wait a month), but my point is if it wasn't for the changes that I made I do not see why anyone would think it was usable. Maybe people under Apache/Apache2/nginx have a different experience and point of view but it was not usable for us.As far as 1.9.12 goes I feel like every day someone new is posting about having an email problem with it. And that really means that I'm not sure that I would trust it to work like my current version.