I am also coming over from a Pre.
. . .
I also miss the email interface. That one I'm hoping I eventually find a good replacement for... I just want to see all my emails one place, with the option to look at a specific box, get compact notifications (not a bajillion for different emails, half of which are garbage), and easily delete items like spam from the main list (oh, I miss swiping them off screen - holding on an email and then selecting delete is a big slow down that drives me to my computer if I get a pile of spam). I also miss my keyboard badly - am trying the 'good' keyboard replacements recommended here, but it is so frustrating to have them all guess wrong repeatedly and then not even let me fix the word, even after the slower typing. . .
I am liking swype, although I'm still sort of slow with it. But it often guesses right, and it lets me manually fix anything it guesses wrong, and when I nail a word, it's very fast. I also sort of like that somebody took the trouble to think, "We have a smooth keyboard with no distinct keys. What new things can we do with that, and how can we optimize it?"
I miss cards. The card-like task switcher is certainly better than the other things I tried, but it's clunky and slow and inelegant compared to live cards. I especially miss cards when I want to use two applications together (typing info from an email into some other aplpication, for instance). I also find it frustrating that the OS randomly decides to close apps I would like to keep open, and doesn't close apps that I am done with, although the task switched lets me close things.
I REALLY miss "swipe to delete". I get a lot of email, and it's really a nuisance to have to open or touch-hold each one that I want to get rid of. It's also frustrating that different apps handle "go back" in different ways.
I miss having buttons handy for whatever I am most likely to want to do. Sometimes I have to scroll all the way to the bottom of an email to delete it. (And sometimes not. I haven't figured out the rule.) I have to go into the menus to reply to an email, or to start a new one. Why? Why not put the most common choices right there at the bottom of every view? And it's really annoying that notifications have to be manually deleted, and the notification thing doesn't just know that I've opened email.
I REALLY miss "just type". I didn't realize how much I used that. A lot of my interface frustatrations will lessen as I learn my way around and move into this OS (currently, it asks "which browser do you want to use to complete this task" all too often. I need to pick one and set a default.) But a lot of interface stuff was just better thought out and better integrated on the Pre.
Some things are better: It's much easier to edit text with the little grabbable "end of selection" bars than it was on the Pre. I can tell whether K9 is failing to download email because there's nothing to download or because of some communication problem. It's smoother and more responsive in general, although I have had the "phone doesn't work" problem.
I wish there was a shiny new WebOS phone that I expected to be supported. I think I can get used to this. Debating whether I need to relpace the unit due to the "can't answer phone" problem.