I have been using IHostASP.net for about 6 months. I have been extremely pleased with my site speed. I have paid them to do every upgrade to DNN as it came along. However, somewhere along the line I noticed my site logs were showing a huge number of exceptions. Since I never touch the code, I asked support and got this response:
"This does not look good, looks like you have duplicate records in your database that are interfering with the DNN. My recommendation is to restore your database from a backup set pre-dating first occurrence of this issue."
Well, I don't watch the log that carefully, so I don't have a clue what to back up to. I don't have any modules on board other than the core. I did notice that after the last upgrade that they did for me, there were modules showing available for install, that were already installed. ??? So, to "clean things up", I decided to let the admin function install them again. I thought it couldn't hurt anything. So, maybe that was the culprit. I consider myself hosed with no known reason for the problem.
The speed of the site still seems good, and you can't tell from the front end. So, my plan is to start the site from scratch with the stable 4.5.1, and see how it goes. I am still going to stick with them. I may now learn to upgrade myself.