Full Wort Boil on a Glasstop Electric Range

This is 5.5 gallons of wort that I got to a boil on my glasstop electric range.  After I got the first and second runnings into the kettle I believe my wort was at around 155 degrees F.  With this towel secured around the pot, I got to a boil in approximately 22 minutes.  

When I first started trying to do all grain I had stuck to 4 gallon batches that barely fit in my 5 gallon pot.  I wanted to be able to do 5 gallon batches, but I wasn't sure my stove could get all that wort to a boil.  I ended up buying this 7.5 gallon pot with the self-justification that if I couldn't get the full 5 gallon batch to boil, I could at least do my 4 gallon batches without having so much wort splashing out during the boil.

I was surprised at how well this towel wrap improved the efficiency of my boil.  When I did my first batch of extract, it took me 40 minutes to get a mere 3.5 gallons of wort to a boil from 155 degrees F.  It seems like the towel made a huge difference.  I left a couple of inches between the towel and the bottom of the pot to avoid having the towel burn.  I also watched the pot in case the towel slipped (which it didn't).

I should note that I brought this to a boil with a lid on, which I removed when the wort got up to around 208 degrees F.  I gotten my last two 4 gallon batches up to a boil with the lid on and not noticed any DMS character, so I went ahead and did it on this beer.  This one's still in the fermenter, so I can't be sure there weren't any problems caused by the lid.