If you source a good vr6 engine then it's a good bet. They are really solid engines if they have been maintained, if not it can be costly to replace parts. A complete running vr6 corrado is the best doner, then mk3. They can be found for under 1k but check history carefully.
If you are handy with spanners then the actual swapping over of the engines is really easy. I found the bits that took time and are fidly is the wiring, prepping and painting the engine bay, fitting the clocks & pedalbox. None of it is hard, just time consuming.
There are plenty of mk2 vr6's out there where the engine has been thrown in quickly with no thought to upgrading brakes and suspension, they will obviously handle and stop badly! If the car has been upgraded properly and has the correct front springs they handle nicely.
If I drive normally I see 31-33mpg about the same as the 1.8 carb it replaced. Obviously if you floor it eveywhere then you will see 20mpg which isn't great!
The sound is amazing so you should do it!!!
