I've got two cases, the Caudabe Lucid Clear (Silver Metallic) and the Spigen Crystal Shell (Rose Gold).
The Caudabe is definitely the most elegant of the two. It fits the X beautifully and the silver edging complements the colour really nicely. It helps retain that premium feel. There is a slightly extended lip just above the lightning port - not sure if this is for comfort when swiping or to help reinforce that area, but it's quite a nice touch. Buttons are easy to access, but not protected in any way. It is a very slippery case and a fingerprint magnet on the rear.
The Spigen is also a very attractive case, though not for those preferring the minimalist look! I feel confident that my X will survive a few knocks with this on and it makes it easy to grip thus reducing the chance of a drop in the first place. It fits the X very snugly (no "give" in the material anywhere) and all buttons are responsive despite being fully covered. The rose gold colour suits my silver X very well. Like the Caudabe, it is also prone to fingerprints and smudges on the rear. It also doesn't slip into a pocket so easily due to being so grippy.
Any questions, please fire away. Here's some pics of the Caudabe first....