if you need a great data plan then yes i would switch otherwise no.
as far as service goes with Sprint i have had no problems roaming throughout Wyoming, Montana and Idaho. Yes you do want a plan that has unlimited roaming, while i was in Wyoming my phone was constantly roaming but the signal was great (I have a unlimited roaming plan). there are presently no Sprint Stores in Wyoming or in central and eastern Montana I do not know about Colorado. in other words no quick fix if you have a problem, you will have to take care of all your tech or phone replacement and phone insurance issues by calling in. that in itself can be a daunting task with Sprint if you do not have patience, their last screw up took two months for me to get straightened out. on the up side i now have a $10 Vision access pack with unlimited data for both phones
Just my two cents.