I would like to know this answer as well.
I currently have an enV and love it. The EMS works great and allows me to send over 160 character text messages to other Verizon phones.
However I was looking to buy an HTC Touch Pro for Verizon and was curious to know whether or not my friends would get the error once I switched from phone to smartphone.
I read the following site but it is really outdated:
http://pdaphonehome.com/forums/samsu...haracters.html
That may be some help but I'm sure someone else on here may have newer info.
Hope this helps