Also, did you check your EA cache folder size ?
Xcache is better than EA. At least xcache will not store any cache file on your hard disk like EA, and thus saves space.
Storing cache files on disk is not that bad if you server is not disk I/O bound or have shortage on disk space. PHP can load the cache from disk faster when PHP is restarted.
Storing cache file in memory only when you have enough memory to spare, otherwise, it will cause problem, especially for memory bound server. memory cache will be lost when php restarts.
Aware of the bottle neck of your server and choose your software wisely.
Anewday,
If your server I/O wait can be as high as 50%, your server is disk I/O bound, not much LSWS can do about it other than reducing the disk I/O or using faster disks. You need find out the process causing the high I/O wait first. And load around 1 or 2 is not high to me at all.