Chabi,
From my experience, these are both top-notch bins. I looked at both about two months ago and after just spending over $1600 on a pair of 8.5x42 ELs, my wallet did some deciding for me.
In all seriousness, I think that they are both optical equals. You will find slight differences in ER (15mm for the EL, 14mm for the SLCs), you will find that the SLCs are heavier (although in my humble opinion, built better) and the EL ergonomics are really both unique and fantastic.
If you look at both side by side and decide that you want to spend the extra $500, you will be ahead only by slightly better ergos and lighter weight. For me personally, my 10x42 SLCs are here to stay. As for my 8.5x42 ELs, I'm not so sure, as they do not fit me as well as the SLCs.
Remember, it is really up to you, as they have to fit you, and not anyone else.
Rgds,
Steffan