Bajafox, that's due to your inadequate ventilation more than anything. Wouldn't moving the ballast outside the grow room (as simple as drilling 1 hole and a piece of tape to lightproof it) have fixed the issue, or perhaps getting a better fan. The 200 bucks you probably spent on the digital when you already had a magnetic could of been used to a) buy a room ac and ran it for a couple months b) buy a better exhaust fan c) buy an awesome air cooled hood d) got you a CO2 setup, with CO2, with your temps, CO2 would help not kill your plants.
Also, if its getting 100 degrees in your cab, you definitely need to rethink your approach. Whats the point of having a 600w if you can only run it at 350 watt because your grow room is inadequate to deal with the heat?
Its like buying a big fin for your car. Technically it helps you stay on the road at high speeds - but your car doesn't go fast enough to need it. I think most people just buy it because it seems 'cool'. Yes, digital ballasts are sexy, but they don't make sense yet. Id like to thank all you early adopters of it for making it profitable for a company to give you beta testing products, but until it is as reliable as a magnetic and closer to the same price, whats the point? In their main function, turning the light on and keeping it on, Magnetics rule the day due to reliability and cost. Its not like its a car and people are going to see it, its just sitting in a closet or a room somewhere.
If money is no object and you are OK with digital reliability, go for it. Most people look at the cost vs performance. Magnetics are cheaper in both short term and long term. If you bought a digital today, by the time you saved the difference in energy it will be outdated and we will have plasma lights. Heat and Weight are the only 2 things that digital has over magnetic, and I think I can live with a heavy box that puts out a little more heat, especially when it can be put outside the cabinet.
