I have owned the EBS Valve Drive and currently use the Carl Martin on my main board. No contest, Carl Martin is more flexible, has much better EQ and function more like a tube preamp (i.e. how hard you strike the string, impacts od). I have no issue in getting more detailed and technical but if you are looking to warm up your tone Carl Martin any day of the week. EBS is a good overdrive, but a little bit of a one trick pony in my opinion and certainly not best suited to warm/liven up tone.