I utilized LogMeIn Rescue to support a few managed services clients. This tool would be appropriate also for SMB to Enterprise level IT organizations to support their user base or to provide support for remote users. I especially appreciated the excellent support for mobile devices at the time. I rarely had connectivity or any issues with the product.
I started using a Bomgar appliance, but the maintenance of updates, usage, setup, need to keep networking correctly setup, and the EOL eventually turned me off. I prefer the cloud portal model for LogMeIn Rescue. You always have the current product available to you, though the monthly cost was higher. In the end it was just overall easier to use and worked as well or better with less effort for me in the long run. Your mileage may vary depending on your needs.