Re: Windows 10 Mobile insider preview as daily OS
I'm having no issues, myself. It gets better and better every build. Smoother, more stable, and better battery life. I still have graphical and UI glitches and it's hardly perfect but I'm happy using it as my daily driver. Just don't expect all sunshine and rainbows. I had a random reboot today. I hadn't had one for weeks before that but it's still worth pointing out that it happened recently. There are still occasional hangs and freezes, and there are still unfixed bugs. I think you'll be find giving it a try but I suggest doing a hard reset after you install the latest build.
Again, I'm happy and I've been using it for months on my Lumia 830 (and I had it on a Lumia 520 for a long time before a touch screen defect forced me to retire the phone). It's not perfect, but in my opinion it's worth the upgrade. I have a Lumia 640 with Windows Phone 8.1 and it just feels outdated now.