I got an ATG gun last year and I do like it, it holds things very well. The only thing I don't like about it is accuracy. Because its so big I find it hard to put the tape right where I need it, like on edges. I really have to work on that when I use it (if accuracy of the tape is an issue that is).
I do like the Tombo mono multi glue though. That stuff works very well. I use the tip side and just a little will hold my card or pages, even embelishments. One little container lasts me a long time. I buy it in bulk and it comes out to be about $2 a bottle.
I also use the scor tape and really like that stuff too. But I don't use it on my cards, unless its got a lot of embossed layers, cause it holds those types of things very well. And I like the scor tape better than the red line because I can tear it, don't have to cut it. I find it on blogs for sale (bulk buys) and its really a good deal.
I did buy the 1/8 inch scor tape but I'm not impressed with that. The inner cardboard circle that keeps it together is comign off, the sticky tape underneath it is coming loose so its kind of a mess to use, but I'm getting all that I can out of it. I had the same size last year and didn't have that problem. That size is just cut so thin that its wobbly when you use it. No problems with the other sizes though.
I still have the tombo snail though, but I only use that for little things. Its not my go to glue any longer. And when I do use it, I run the snail very slowly because it goes on better and then rub rub rub on the item to make sure it secures it.