The direction that this thread is heading incites me to inject this.
First, I believe that the word recovery is not accurate. I believe that what you're referring to is reset speed. The amount of time required to 'reset' between objects detected.
Recovery to me means that something has been lost, therefore needing 'recovery'. Like a lost coin or relic that we 'recover'.
Now on to speed.
It has been my experience that the more basic a machine is the 'faster' it is, and inversly, the more information that a machine is capable of delivering to the user the slower it is.....most else being equal. Older basic designs incorporate potentiameters<sp>, variable resistors, and the like, have single tone, have no notch capability, and have no display. Therefore they are 'faster'.
More complex newer digital designs that deliver tons of information to the user with multiple tones and a display screen are processing far more information, and that takes time. If you want adjustable ground balance, or auto ground balance, or ground balance tracking, or tracking offset, all of those require processor capacity. If you want a numeric TID, firmware must be written to interpret what the machine sees into that value, and then display it. That takes more processor capacity. Etc... You see where this is going?
For the amount of information that an Xterra is capable of displaying, and all of the auto/adjustable features that it has, it is in no way a slow machine. Compared to other newer MineLab machines, it's actually pretty quick. The FBS machines process more and different information than the Xterra's, so a direct comparison is not easy, but if you want to experience slow....get an Explorer. The E-Trac and FBS2 CTX3030 both have larger faster processors, so they remain pretty fast even though they are processing HUGE amounts of information and providing it to the user. The larger and more capable the procesor required, the more firmware required to process all of that digital information, the multiple tones available for targets, and the display that delivers it all cost money, and is what some of us are willing to pay for.
If you decide that you don't want or need that information, then don't buy a MineLab. If a few tones, notchable disc, adjustable GB, adjustable SENS, and a digital display are all that you want, a Fisher, Teknetics, or something along those lines might be for you, and they will seem 'faster'.
And if that's too much, then a Tesoro might be right up your ally. Depending on how elaborate a model you choose, it might be either like lightning or not so fast.
Just remember, unless you're in a competitive hunt, this isn't a race. There's a reason that MineLab owners are successful....slow or not.