I have a stanley glue pro which automatically shuts off and has high and low settings, it has different tips, I use the long tube one, and it works great. Heats up in reasonable time, doesn't drip much, and likely only does because I get impatient for it to heat up (mainly due to being low on sockets whenever I find myself in need of it). It is great for filling hard to reach areas with glue as it's very liquidy (can't recall the term) due to the temperature.
I think I paid $70 for it, it's been well worth the investment.
https://www.amazon.ca/Stanley-GR100-Glue-Pro-DualMelt-Glue/dp/B0000223U7I have gone through a lot of cheap ones too, I have one that I use exclusively for black hot glue, can't recall the name/brand on that but if I had the choice I'd use two of these.
edit:just looked at that 3m gun and man, it looks fancy, but sure is pricy. It seems like it might be difficult to do small/accurate blobs with the trigger like that, but would be easier on the hands for heavy glueing.
edit 2: just saw that you made your choice, looks interesting, but is a little too thick and the end for my taste, seems like it would be difficult to get into tight spaces.
As far as glue sticks, get the super long ones, I just use local dollar store stuff and it works fine, I could never, ever go back to the standard ones, they are just useless, they run out so quickly, you have a weird period where they fall out all the time until they start getting deep enough in, same with long but it's a lot less often.