I only got my first WP7.5 device a Lumia 800 about 5-6 months ago, and have been using it on and off with my other devices. I was really in love with its homescreen, but felt that it could do with more customisation. Flashing 7.8 on my lumia 800 gave me that amazing homescreen that I really love. But like OP mentioned, there are little things here and there that stopped me from using it full time.
- Notifications is one thing, like whatsapp for example, if you don't have it on your homescreen, or lower part of your live tiles which you have to scroll down too, its pretty easy to miss the toast notification and forget about it. Frankly, when i was watching the WP8 keynote live stream, I was hoping that at some point Joe Belfiore would say, "Guess what, now you can swipe to the right to access to your notifications centre!" but obviously that did not happen... The lack of notifications centre also meant that when you have lots of new notifications from various sources, like emails, sms, whatsapp, facebook, twitter, etc, you have to go into one app, check it, then out. Then in, then out again to another app. It takes up a lot of time. So I hope MS is listening and trying to include this in the new Apollo+ as fast as humanly possible.
- Some minor settings are still missing, but the gap has been closed up slightly since WP8, but still not as much as I would like.
- Apps. There are 2 apps that I use on a daily basis. Whatsapp and Board Express. Whatsapp take painfully long to open, even compared to an old BBOS 5 Curve 8520, even if you restore it from recently used apps, it still takes a while to resume. Board Express is just painful to use, buggy laggy. There have been a couple of threads saying that there might be new ones coming, like from the developer of "Communities" for WebOS i think, or the developer for Tapatalk on BBOS, but they never did come. Then of course every now and again, there's news about developers leaving the platform, or no longer updating their apps (their loss). Which i think is a huge pity seeing that with the risk of not having enough users to justify the developer in comparison to iOS or Android, there is also the chance of making a name for themselves is a platform that is not as crowded as the 2 giants.
But of course there are some pretty cool stuffs that I love in WP8, like the lockscreen, the ability to change the refresh tab to other buttons in IE, Kids corner, etc. Overall there are things that I love, and things that I hate, like in every platform out there, but sadly the things that I hate I can't live without, and the things that I love aren't enough to make me stick to it for long. But i strongly believe that eventually all these holes will be plugged.
Its a great platform, but sadly not suitable for my needs, but i really hope MS will pull through. I really hope that WP8 will catch on with consumers. Honestly, i don't want a duopoly of iOS and Android on the market.