It will all come down to how it drives, paper stats can’t tell you everything about a car, Pistonheads just proved that to me with the M4 GTS lap of Combe they have on their site, 500bhp, massive Pilot sport Cup 2 rubber, they show the driver doing ~4 second a lap quicker than what I can do at Combe in my MX5 on road tyres and it looked a handful, like he was trying, too much weight, if I had half that power and sticky tyres I’d smash that, I could probably get close just running the same tyre.
The 124 will have reasonable power for its weights and its chassis balance shouldn’t be underestimated, I’ve not got around to testing my SS up against my Mazda at the same venue but even though the Mazda feels gutless I think the SS would struggle to match the 5 around a technical lap, and it can barely crack 60 in 8s.
all told though if the price is to be that much higher the 124 needs to offer another level of performance to the Mazda not broadly the same, can’t see it doing that without the 1.7 Tbi.