http://www.emrandhipaa.com/katherine/2013/02/26/one-fifth-of-physician-practices-might-switch-emrs/comment-page-1/#comment-171759 This is a topic I have been aware of and following since last one year when I have seen a rise in 'switchers'. The reasons cited are all true of course, but for most part, that is the 'logic' cited when asked for reasons for switching.
John as you have rightly said, no one offers everything, and these are issues faced by everyone. Yet, only few switch.
In majority of the cases I surveyed informally, it is an emotional decision based on dissatisfaction with how their Vendor handled the situation.
I have actually seen practices switch from Vendor A to Vendor B and from Vendor B to Vendor A - for the EXACT SAME REASON!
Message for Vendors:
You may have a good web based EMR system, focus on Customer Service
Message for Physicians:
Chances are Switching will not solve your problems. Make your Vendor a Partner and work with them. Switching will be expensive, painful and perhaps not solve the problems.