I wrote HTC support to tell them there Messaging application is poorly done and moves like a slug. Thought I'd share there response along with my original email. HTC won't get my money in the future.
"I have just about had it with HTC Devices. I have owned the Mogul, Touch Pro, & Touch Pro 2. I have updated my Touch Pro 2 to Windows 6.5. The phone and HTC Sense look great. I really enjoy the integration of the messaging with the Sense interface. But the speed is UNBEARABLE! The phone is a slug after 150 SMS messages. This NEEDS to be ADDRESSED by HTC's development team. The HTC messaging application is TOO SLOW. Please stop ignoring Windows 6.5 Touch Pro 2 users by not fixing a massive speed bug."
HTC's response:
"I realize it can be very frustrating for the text messaging application to be slow. From what you have stated it seems this issue starts happing when you have reached over 150-text message. To keep your phone in good working condition HTC recommends customers not exceed over 100 messages. To resolve this issue I recommend you delete some of your old text messages. I apologize for any inconvenience this has caused."
AKA we know there is a problem but we are not fixing it so limit your SMS messages to 100. Thanks HTC for the great support.