They're basically the same brush, use all the same components, except of course the front of the 360U will rotate to use as a gravity feed with a 1/16 ounce cup. The 105, 155 and 360U are all the same except for being gravity fed, siphon fed and both respectively. The 105 comes with a fine tip, needle and regulator and you can order a 3155 Anthem that uses the same fine parts or you could buy them seperately and use them in any of those brushes. I've used a 360 for a long time and have had good luck with it. I sent it back to Badger about this time last year to have the needle bearing replaced and while they had it they also replaced the collar that allows the front to rotate. There's a lifetime warranty on those parts and no hassle getting them replaced if you need to. You just pay postage to ship it to them and they take care of the rest. The cup isn't very big but I've found it useful. I'm sure either brush will serve you well.
Tony
PS...This is not an infomercial. I use Iwata brushes also.