1. Has anyone had any issues with hitting their knees on the Gas Tank (and what about a mountain feedbag?)?
2. If you have a Tangle bag, do you wish you would have just bought a full frame bag?
Just looking for some insight.
1. I have used the gas tank on most of my bikes, including the mtb tandem and cross bike, never hit my knees on them. It's very versatile and moves around my stable when needed. Fits every bike (does not go well with the Jandd frame bag unless you modify the Velcro closure on it!)
2. I opted to get the tangle bag because I wanted the flexability do fit it on a number of bikes and, importantly, I still like using water bottles. They are a little hard to get out of the cages with the framebag in place but nothing I can't deal with. I have the mountain one which also fits my cross bike (specialized singlecross 58cm) fine. I can see why one would want to have a full size frame bag though. Maybe I will go that way one day. I'm still dreaming of getting my girlfriend into bikepacking and go out on adventures on the tandem. That has a lot of frame to fit bags in! Would be expensive but worth it!
Hope that helps a bit.