well the Zetec actually makes quite a bit of torque, almost always as much or torque than power. as an example, my old turbo Zetec made 200WHP and 220WTQ (it was faster than a lightly modded late SN95 GT) with a T3 60 trim turbo running 10PSI and on a dyno that is notorious for being about 10% low compared to a dynojet. (not saying one is better or more accurate than the other, just that most people use a dynojet and this dyno reads low compared to them). now that much torque with the V6 comes on quite low in the RPM band and causes traction issues, where with the Zetec it ramps up to that much as the boost comes on (started building boost with that turbo by 2500RPMs and had full boost by 3500). this means i could launch it hard at 4000RPMs and not have any traction issues, the clutch would grab, the tires would chirp and i would be off and immediately start to build boost (and it would throw your ass in the seat harder than even my 3L).
as far as cost, I rebuilt the engine, built the turbo setup, installed Ksports, pre98 SVT body kit, built the trans with a torsen, all for about $5500. now i admit that i should have used different pistons, but thats a different matter and it would have added only about $100 to the cost (in fact for that power level i could have left the engine stock but i was planning on going for over 300WHP). now at the time medium mileage stock SVTs in good condition were selling for more than that. so i could build a Zetec to much greater power and handling levels for less than a stock SVT, without the drawbacks that come with the SVT (traction, weak diffs, and spun rod bearings). and i could still get almost 30MPG on the highway, even with having fun, so which would you chose? I know where my money would go.
I admit that its not as easy to build a Zetec to that power for less than a good condition SVT these days, but if your not planning on over 250WHP then it can be done on the stock block which will save quite a bit of money (250WHP is really about the limit of this platform without going crazy trying to take care of wheel spin anyways). If you do it with a pre98 you dont even have to change out the diff, although i still would just for the increased traction from the LSD, but its not necessary to prevent it from blowing up.
you mention CSVT#49 and his build, do you know how much he has spent (or is going to spend total since he isnt finished yet) on his build? im not positive but i seem to recall $13,000 being thrown around as a rough estimate. If he is still only running 13s after all that then it seems like wasted money to me, since 13s can be had in a Zetec with 200-250WHP. im not saying his build isnt epically awesome, just that if thats all the car runs there are much cheaper ways to get there, including a turbo Zetec which is way more fun than a 3L (I've had both, care to take a guess at which one i enjoyed more).
), better final drive ratio, lighter, easier to work on, higher revving (if built right), fewer trans linkage problems, better diff., can make just as much power as a modded 2.5, reliability, traction control (if you want it), and i know there are a few things i'm missing that i'll think of later.