Well, I have an Adaptoid and I use it with Project64, right now I'm using real N64 MemPack connected to the controller, and the last debug build version V2 2.1-Debugbuild, downloaded from the rabiddeity's signature date 4/5/2007 10:06AM.
Right now I configure the plugin to use Adaptoid Pak, but have the following issue,
I had tried with a few of my favorites games, like Castlevania, Shadowman, Perfect Dark, Cruisin'USA, Nuclear Strike, etc and all of them worked fine, but there's one, Fighting Force 64 that along with this input plugin makes the emulator runs very slowly, the r4300i in PJ64 status bar show almost 90-95% execution and the VI drops to 20-30, at least on my computer, don't know in a more powerful computer.
Also, I noticed this, if I enabled the Adaptoid pak in the plugin, and start Zelda OoT, the game becomes very slow, if I assign a key to a shortcut for MemP<->AdaptoidP switching, and switch to a MemP simulated memory pak the game runs normally, but when I switch back to Adaptoid Pak, it slow down again.
The same behavior that in Fighting Force, extremely high r4300i emulation, and other cores running between 0-4% execution, when configured to use Adaptoid Pak, runs normal if switch to MemPack mode.
I know that Zelda doesn't use the MemPack, it used a battery backed ram, but it seems strange to me that this game exhibit this behavior.
Also noted this, if I use the Adaptoid Plugin that comes with Project64 1.6, Zelda:OoT runs normal, other memory pack based games runs fine, with a few exceptions, mainly in games like SuperMan, DukeNukem Zero Hour, Fighting Force

again, when the game doesn't seem to recognize that I have a real MemPack plugged on my controller, and ask me to insert it over and over again, which was at last the main reason for which I decided to try NRage plugin.
Also, as a suggestion from squall_leonheart, I uninstalled the adaptoid drivers, to test again the emulator, just windows xp standart usb drivers, and with no luck, the plugin presented the same behavior.