Your cover is really a great lullaby song that could almost put me to sleep (in a good way of course).
Your vocals & guitar are so mellow & excellent! But you know me about the ssss and pppp sounds. When something sounds this close to perfect its the little things like the sss sounds that stand out. I recently got this AVOX processor that has a Sybil setting that takes them out w/o affecting the original track.
The only thing I might do is bring the guitar up just a bit, and the vocals down just a bit, and then mix a very light room reverb into the final mix.
EDITED: After listening on Myspace this sounds much better than the SoundClick version through its streaming compressor. You might still want to do a subtle tweak or two but it's much better there.