Hello there,
I'm currently driving the CPS here as well. A manual one, though. So far I only have light mods on my car since I only got it recently. So far from what I have heard from other owners driving the CPS AUTO, the FC is little higher compared to the Manual one. Optimum BHP is pretty subjective based on the individual. Some can handle a 600bhp machine as a daily driver but some like between the range of 200-300bhp.
In terms of practicality, I would say your Waja would beat the crap out of it since it's a 4-door, compared to the CPS's 2 door. Maintenance is reasonable, definitely cannot be compared to the GTR. CPS is totally not in the same league as the GTR, hahah.
The CPS is a rev-happy engine but don't put too high of an expectation on it, since you compared it with a GTR.
But overall am very happy with the car. It might lose out on pure power but it triumphs in the handling side of things. Very nice going up Genting, just keep it within the high rev range.