I doubt David Ashman looks at these threads, but here are my issues (besides the noted bugs). I emailed him about #1 and #2. If you feel the same way, maybe make a request.
1. No option to preview an email and have it stay UNREAD. There's an option to "Mark Read on Clear". I don't think that option makes sense since ANY action you take marks it as read already (Previewing, Clearing, Open in Mail.app). I'd prefer that option be changed to "Mark Read on Preview".
I like to preview my messages and then i'll use the "Clear" function to mark it read and clear the notification. This is how Lockinfo used to work.
2. Twitter feed as a widget. I understand why he did this, but i'd prefer to see my Twitter feed as a notification (it's an extra tap to pull down your widgets). I think you just need twitter feed and twitter notifications buttons.
Also, my feed won't load. Just sits at "Loading".
I think all the widgets should just get an icon icon like mail, messages, etc. instead of being buried under widgets.
3. No idea what "Full Previews" does. I don't see a difference with this toggled on or off (this is in the mail notification settings).