Last post was almost two years ago. Still no definite answer to the question. well.. here's my RM2 (used to be 2 cents but what can you do with that nowadays).
Displacement = torque.
Horsepower = (torque x RPM) / 5252
So, that's up to personal pref. More displacement means more torque and more expensive road tax and more fuel for standard driving and a much heavier engine. Forced induction is the best if you wanna go for balls shrinking WHoa!! factor. Turbo lag isnt that much of a problem nowadays since there's this new `anti-lag' turbine design (some sort of a VTEC for turbo) hehehe..
Stroker kit and such depends on the rod ratio of the engine and as such can be stressful on the side wall unless some machining were done...
And if you're doing the machining... then better do the mod with the block coz it may cost almost the same anyway.
I can buy a 3Ghz Pentium Chip and overclock it to 3.6 and i can buy a 3.6Ghz Pentium Chip. The former might cost a lil cheaper but how long can it run? 2 minutes the most (Skidding off the track here)
We want power and reliability. So in my opinion..
Yes.. there is a replacement for displacement and its called VTEC.
:D Seriously.. for me.. i'd put my car on a diet and lose some weight since its the most cost effective way to affect almost every aspect of your car performance (other than your monthly premium, road tax and insurance coverage)