what ever one you use, jut make sure it is 3 or 4, because i read in a mechanics magazine for subaru, that if you use the dot 5 some new kind, it has repeling characteristics. also it said that it is next to impossible to bleed out all of the dot 3 or the dot 4 out of the system. here is the site address for you to look at, it was in a magazine but you can also look at it online
I have no experience with motul but i use ATE, know a number of people who use ATE, and it came to me under high praise, so I voted for it. I have been very happy with it, but the fluid i replaced with it was old, stock, and SHOT so I can't make a real accurate assesment.
if you drive hard enough to need this kind of fluid, the OEM won't last that long i left my OEM in for about 24k miles which was the equivalent of about 1.75 years. and it was shot. that was some of the nastiest brake fluid i have ever seen. i'll be replacing the ATE once it gets warm again, so a total time of about 10-12 months. I've had no fade issues and I don't expect to, but I'd rather replace the fluid before it fails
its not very difficult to change brake fluid. all you need is a friend. if you have no friend, get some speedbleeders. actually, even if you have a friend, the speedbleeders make it way easier.
I use ATE Super Blue only because I picked a bunch up cheap. But it is great! Never used Motul, but I know a few people who do and the have no problems. You just bleed the brakes once a year and flush/fill every other year.