Review on the Mrjosh pulley:
This pulley had been installed on my car for about a week, and I am very satisfied with it. I felt the increase in power, like faster reving, and it just like making my car lighter to drive. I think this pulley provide a decent gains in performance, and it should gives a 6-8hp gains (I haven't dyno yet!). The quality is great too!

My current mod:
Torque Chip II
Short ram air intake w/KNN filter (ebay)
Mrjosh pulley (ebay)
Whiteline rear sway bar w/HD mounts & endlinks
Cusco rear lower arm bar
Front strut bar
Piaa Super Plasma (The color is great, but is not bright at all!)
*I just order the Piaa Super Plasma GT-X, and hope that it will be brighter as what they claim

Best buy mod for power (consider from my current mod list!):
1) Torque Chip II
2) Mrjosh Pulley
3) Short ram air intake w/KNN filter

Best buy mod for suspension:
1) Whiteline rear sway bar
2) Front strut bar
3) Cusco rear lower arm bar

All the mod are installed at a different time period, so I can really tell the difference for each mod:

Torque Chip II
Pro: It will make a huge improvement in the 3000/up rev range

Con: My car had a rough idle in the first two weeks after installed the chip, however it will eventually disappear

Mrjosh Pulley
Pro: Very good performance mod. Faster response/faster accel. Is a relatively cheap/effective mod to get. Recommand it!

Con: Non so far! Some people suggest not to install it since it may casue damage to the bearing

Short ram air intake w/KNN filter (ebay)
Pro: I love the sound it produce in WOT. wohmmMMWOOMMMMM
Rev a little higher! More power in the higher rev range

Con: In my opinion, I think it causes my car to lost some low end torque. It made me to hate the stop/go traffic!

Whiteline rear sway bar w/HD mounts & endlinks
Pro: This is a must for any impreza. It will make the car to drive in the neutral, and the adjustable settings really help to provide a setting that fit the driver

Con: SQUEAK... please help me to solve this problem!!!

Front strut bar
Pro: Better handling in a corner

Con: This mod is installed before I got my rear sway bar. The bar made my car UNDERSTEER like mad. I suggest to get the rear strut bar/rear sway bar along with it

Cusco rear lower arm bar
Pro: I don't see any difference in the dry condition. However, I do notice that my rear end is firmer when running on the snow. It helps my car to run better in the straight, and now I can run at a higher speed on the snow

Con: Can't see improvement in cornering. I think it will help on the track, but not on the street

Piaa Super Plasma
Pro: Nice color

Con: They claim that it will produce a 130w/110w of lights, and that is BS