RTM? I think not. The swear words are automatically censored. ****!
Ok, so here's how the fast ring screwed me over. I was on the slow ring on my Lumia 520, my daily driver. But as you know, the slow ring has been stuck on 10166 for ages now. It was working ok but I was getting frustrated by the loading/resuming screens and clearly it was playing on my patience. Every time I looked online a new build would come on to the fast ring 240,536, 572 or whatever. The bugs seemed to be getting fixed. The battery life was being improved and the builds were getting faster. Yet none of them were making the slow ring. So when 581 came out (It cleared the bug of having to go back to 8.1 I think) I jumped ship to the fast ring. The first installation, I got ****ed by the dropbox app which didn't uninstall properly(I removed it while making space for the update, didn't use it anyway), and the update kept giving me an error because of it during that annoying preparing to install time. I had to reset the phone and that somehow it went to ****. Ended up with a win10 with no phone app, no messaging app, no store app!! Had to go back to 8.1. (******* dropbox!) Anyway updated to 10581. Working ok. Still a bit slow but much faster than 10166. Liked the new lock screen thing where only the date went up(even that wasn't there on 166). But there was a bug in the storage app which had me worried. Couple of days later 10586.11 comes up. Installs fine, storage app issue is fixed. Overall the performance was very good. Pretty close to the finished product. 2 days, no problem. Battery life significantly improved. But then, some device hub BS popped up, asked for a restart. The notification wouldn't go away nor would it respond when I tapped it. So I switched off the phone, switched it on again and voila boot-loop! ******* hell man. Hard reset won't work, don't even try it if it happens to you. Recovery tool-back to 8.1. I'm staying here on 8.1 for now. Tbh, kind of forgot that 8.1 was pretty damn good. I'm not complaining per se. I read the changelog, knew there's a bug. But in my defense l, it did say that the bug hit if you had reset your phone in 581 and it also said that the bug showed up at installation. So I'm just saying none of those applied in my case, it installed fine, worked beautifully for 2 days and then died. So just a disclaimer to people downloading/downloaded the build, don't switch off your phone
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About this build being RTM, yes, it did look like it but with a bug like this, I'm not sure.
PS: This site is a bloody horrible experience on WP.