Over the past 5 years we were with TELUS and loved the MIKE phones, but the US carriers dropped the service and TELUS did not have any other solution. We found BELL had a PTT service which worked well for about a bit but our rep changed about a dozen times in a year. It was real frustrating working with BELL. We then tried to move our PTT to Rogers. Thier product was horrible, and every driver had to click 3 buttons, then find a contact just to push the button which ROGERS couldn't come up with a work around, so it didn't work out.
We are now back with TELUS and no PTT phones as all the drivers have their own phone and are reliable.
Overall, the customer service for all of them is terrible - each time you call tech support they tell you that it's your device and you need to upgrade the firmware and there is no resolution until you can upgrade your phone and when it still fails they say the device is defective. Magically a couple hours later it is fixed. There is no way it's always the firmware or the device. Each company always charges added fees and every month it requires a phone call to reverse the 80 cents here and the 2 dollars there.
Each one has their service deficiencies and even more now that most services are going to LTE. Once you leave the a larger city and get off the main highway you have dropped calls.
A story about BELL - 3 yrs ago. We had lots of troubles with dropped calls and then no service for up to an hour unless we rebooted the phone. This was happening to all phones. Of course tech support said it was firmware related. I know a guy that works at BELL NOC. He put me through to one of their cell phone network guys who worked with me as I drove around and tracked my phone. We found out that a tower near our facility would not release my phone number to the next tower In fact it was a bug that was happening to a lot of people but only if they stayed on the tower for over 20 minutes. How it works, as I was told, is that my phone number links to a tower and the tower will give my phone number to all the towers that I may traverse to next. Once my signal is stronger at the neighbor tower I will be seamlessly transferred to that tower. This was not what was happening. Along the 401 corridor, their towers are bi -directional towers meaning they send out a signal quite far for 401 traffic as opposed to city towers which broadcast smaller distances but 360 degrees. The 401 tower close to my work was not aware of one of the city towers which I should have picked up. This was causing all the problems which took 6 months to fully fix.
To summarize, all 3 are the same - go with the best price for the service you need. You get no bonus or advantage with staying long term with any of them.