for what it's worth, i'd recommend waiting until you start classes to spend money on E&Es. i've found that some professors are just too particularized for the supplements to be of any help. for example, i bought the civ pro one at the beginning of the year because it's supposed to be infamous, and i admit it's a solid book, but my civ pro professor is just to specific with his teaching methods for the E&E to be of any assistance. i get everything i need for my professor's exam from his lectures and the assigned readings. and now i've wasted $40 on a book that is collecting dust.
I didn't use E&E's much, so I won't comment on them, but I found the Crunchtime books to be pretty universal since they by and large focus on black letter law and exam-application of rules and doctrines. You're obviously going to want to get a great outline for your professor/class. (No, don't make your own. A wheel is a wheel no matter how many times you reinvent it).
Well, I don't really disagree, I am sure making my outlines would have been better, but to me, not significant enough to spend the time doing it. Making outlines for 3 or 4 classes which you usually have as a 1L per semester is going to take quite a lot of time. What I did was get the old outlines the first week of school, and just edit and adjust it as we went by. It worked out fine for me, with a lot less time spent. Although I am sure you are right that the learning process from making them is also beneficial.
I'm not sure about underrated, at my school pretty much everyone seemed obsessed about writing their own outlines. I was one of very few that didn't. But yeah, each to their own, I don't really think other people can tell you how you learn best, we're all different like that. Do whatever feels right for you.