I have been reading here for some time now and finally purchased my own Hawk.
I'm the proud owner of a 2004 black with gold rims (for now) Hawn that's had the exhaust upgraded along with turn signals to LED and fender eliminator.

I looks to have been the pride and joy of an unknown previous owner. I bought if off eBay from a dealer for a song and had it shipped from MA to WI a couple weeks ago. So while I dragging down the sled I'm tossing the Hawk up in my storage at the shop. I did get to ride it for one day before the weather turned.

It sounds like there are some basic mods that most hawks benefit from but I can't find a thread saying what the common upgrades are.

Can someone give me a summary of the most popular upgrades?

 

Well, you should first look into changing your CCT's and R/R as those are maintenance items that may leave you stranded or with a blown motor.

Common upgrades depends on cash and preference, but I found that getting the suspension setup correctly made a huge difference.
Look into Jamie's F4 shock swap for the rear and re-springing and re-valving for the front. Or go with a USD swap.

Here are some other things that I really liked doing to mine, and would be the first for me to do again:
Lightened flywheel
HID retrofit (not just a bulb/harness swap)
16/43 gearing

And some freebies:
Set TPS to 500 ohms
De-PAIR if it hasn't been done yet
Shim the rear shock for a slightly faster turn-in

 

A fuzzy picture, but a picture of her none the less.