Lloyd, I'm not familiar w/ the Acoustic/Performance Strings so for the purpose of this reply I'm going to assume they are the SP (Studio/Perfomance) strings which are Phosphor Bronze and have the bronzed steel E & B strings. I think they are a bit brighter, as you suggest, and I've also found that the strings last longer than any of the other Martin strings I've used. I haven't tried the Elixers yet, I'm being stubborn about the high tech coating business and holding on to that inner need to change strings frequently! Good luck. I'll be interested in other folk's opinions on strings.