Alkyzilla, you ask some good questions.  Yes I bought my zilla new in 88 and had a mild porting performed by CT racing in 1990.  Runing race fuel is not a problem and I usually ride about 8 tanks of fuel a year.  It sits in the winter.  I play in the desert, 1/2 to 3/4 riding at the dunes. the rest is desert trails, washes (moab) or the high mountains of colorado or utah's paiute trails. I am R &R ed the top end many times. Its down to the frame now.  I just got some upgraded shocks from wayne of PEP.   My ability--I have been riding dirt bikes and Atv's for 40 years.  Im 50 now so I like to think I am really fast----but I dont throw caution to the wind like I did 30 yrs ago.
I have a 4x4 trail machine and a raptor I just did hot piston, cam, valves but it is nothing compared to my CT zilla.  I love the Zilla.  Idont mind working on the zilla but I dont want to have to replace a piston every 4 tanks of fuel either.

I have not run my new pipe yet but i did talk to its builder but not in detail about my porting questions.  I will  talk to him and I hope to hear from other builders as well.  Or I will call some if I dont hear an;y;th;ing hear.
I guess I am the type that likes to do some research and hear from many people using the products or at least "In the know" to better make a decission.

I would say I am leaning a dune/play porting----for all I know I already have that from CT.  I just dont know what 20 years of inovation has brought the zilla on porting and what the trade offs are.   I have been out of the performance shopping scene for 20 years so I am trying to get up to speed with options.

In short I am looking for all the power I can get with a powerband that is still very rideable, reliable, but leans to DUNE performance.  I just didnt know if a HRD ( I am just using that term for optomized dune porting) gives you say 10 more hp but cant be trail ridden ....

sorry for the typos..im trying to do this from my phone