What year headunit did you use? I'm looking into options for my 05 WRX.
I used a 2008 or 2009 Legacy GT HEU on mine but, if you notice, I didn't have a choice because Subaru combined the HVAC and HEU into one big POS unit unfortunately. They do have an available separate HVAC unit you can buy from Japan directly that I looked into but it just seems like too much work to me.
I talked my brother into buying a brand new Subaru WRX back in 2005. He's hooked, I think he's a Subaru guy for life now too as he has over 200k miles on his so far and he still loves it. The seats still look like new, he has the original engine, turbo, clutch, transmission, etc.
Anyway, he replaced his HEU with an aftermarket one a few years ago, it's really simple. He loves his b/c it has a built in aux port, usb port, HD radio, has bluetooth, etc. He felt NAV was a waste, I have oem NAV in my wife's '08 Accord and I agree, it's a waste.
Anyway, he bought his a few years ago, it was more back then but now it's pretty cheap - $159 from Crutchfield - you may find it cheaper if you shop it around. Probably sounds dorky but one of things he liked about this was that you can change the text color to display the oem green like the rest of the interior. Plus, his thing is, if it gets ripped off, he's only out a couple hundred bucks. No sense putting something uber-expensive in when it can easily get stolen.
It's a JVC KW-HDR720.
CD receiver with built-in HD Radio AM/FM tuner
built-in MOSFET amplifier (20 watts RMS CEA-2006/50 peak x 4 channels)
plays CDs, CD-Rs, and CD-RWs, including discs loaded with MP3 and WMA files
adjustable illumination (you can select different colors for the display and controls)
fits double-DIN (4"-tall) dash openings
iEQ 3-band parametric equalizer
Burr-Brown 24-bit digital-to-analog converter
built-in iPod and iPhone controls
compatible with optional Bluetooth adapter
inputs: front-panel USB input, front-panel and rear auxiliary inputs
outputs: 4-channel preamp outputs (2.5-volt front and rear)