Perfect, that just helped me make the decision to use my Fix86 easy. Good to know the crossovers are not required if I utilize my VX1000/5i internal system. I was dreading having to find a spot to mount the crossovers. Thanks again for all the info! Ill post and update when all is done.In my opinion, the Fix86 provides the cleaner, flatter signal conversion between these two options, but the PAC is a ton easier to install, since it's a plug and play option versus having to add resistors.
The Fix86 and TWK are two completely different systems, with different purposes. The Fix86 is a specialized factory integration LOC on steroids, and the TWK is a true DSP allowing for customization/control of your sound (Timing/Crossovers/10-Band EQ per channel/Gain/Sound Profiles/Etc).
Oh, and I tossed my passive crossovers, using only the VXi's internal crossover system. My amp is the VX800/8i, which allows me to send a discrete channel of power to each each tweeter and mid-range speaker. I'm also using the VXi's pass-through to feed my sub's amp, which allows me to control the DSP functionality of it, too. It's super clean and allows more flexibility when tuning.
Hope that helps!