I use to have the Typhoon but had some issues with wires breaking at the drysuit plugs, also temperature was just OK but you can not change it, also burntime is just around 60minutes. I have now changed to the Golem Q-Vest and it is great. No need for special hole since you just change your drysuit injection valve. THe vest can be turned OFF-ON from the battery as well as 3 different level. I use mainly level 1 and 2. 3 is really hot and will only use it for 1-2 minutes when I need to roast a bit more... Really great vest. The battery pack is given for about 3 hours obviously depending on the level selected. I did not had the opportunity to do much testing on the burntime yet.