First timer, go easy!

I just put a US nut (Wide Thin/Wide Fat) on my SE Tim Mahoney. Looking at the 2 nuts, they are obviously different materials, the SE nut feels cheap compared to the US nut. They are the same general shape, same width, but I noticed the string spacing is slightly different. The outside E slots are wider on the US nuts. Is this just to compensate for .010 strings, vs the .009's on the SE? To clarify, the slots are not just wider, but in a different spot, the US being wider. So I know I didnt get a Regular nut, since they wider spaced...is this normal? Will I have a problem with this nut? It looks normal spaced on the guitar. Ive got 2 US models, this is my first SE model. Thanks for any info!