Two cars separated by 99bhp, £70,000, eight-tenths from 0–62mph and 40mph at the top end. Not much competition when it comes to image, either: the Vantage is a tailored suit; the BMW, a pair of off-the-peg Levis. Yet draw away from the details and they play much the same role. Both are rapid rear-drive coupes, both aren’t cut out for family life (although the BMW can claim rear seats) and both are just as capable at squashing huge distances as they are vaporising a set of rear tyres. Fortunately, our patented Speed Week scoring system (the car which makes us grin inanely the most, wins) takes price, power and any other numerical comparison out of the equation, levelling the playing field nicely.

Unsurprisingly, it’s the Aston that looks, feels and smells infinitely more exotic. So, given this is a track I’ve never driven, and the sadistic proximity of the concrete walls, I head for the BMW first. I admire its perfect proportions and bulging wheelarches – like a clenched fist in a white leather glove – and say a silent thank you to BMW for not tinkering too much with the standard M2’s design, besides adding proper M car wing mirrors. On paper, the M2 Competition is the car we all wished the M2 had been from the outset: a true, bespoke road racer dry-rubbed with M’s magic dust, rather than an M240i with some extra sauce on the side.

As you’ll have learned earlier, it’s largely down to the engine. Out comes the M2’s single-turbo 3.0-litre straight-six, in goes a twin-turbo version borrowed from the M4, but turned down to 404bhp and 406lb ft of torque. With 10 per cent more power, but another 55kg to carry around, it’s a subtle enhancement, but makes a world of difference. Prod the throttle, and it prods you back – the way it responds is angrier, zingier and a bit more immediate, with a deeper hunger for revs. Keep it pinned and there’s that metallic rasp from the M4 and a lovely linearity to the delivery that makes you forget this is turbocharged at all. A Stanley knife of an engine, then, precise but not particularly threatening…

Unlike the Vantage, which is dominated by a booming, spitting 4.0-litre twin-turbo V8 brute from the house of AMG. It actually feels faster than its 503bhp and 505lb ft, always pumping out energy, constantly poised to smack you back into your seat and light up the rears with a hit of boost. Although tricky to lay down the Vantage’s grunt off the line, in-gear it muscles forward with an alarming snap. Not too long ago, this would be supercar levels of shove… a world away from the tuneful old 4.7-litre V8, which much preferred to convert its 400-odd bhp into noise, not forward motion.

“What’s not to like?” you’ll say, but there are two problems. The first is the eight-speed ZF auto: it’s slick enough but can’t match the urgency of the V8, particularly on downshifts. Secondly, as a result of the Vantage’s overall keenness to respond to the slightest input instantaneously, it doesn’t feel particularly… like an Aston. It’s fightier, torquier, more in your face than we’re used to, so requires some light cranial recalibration.

The M2 fizzes with energy, hopping off kerbs, jinking through the chicane, lighting up its tyres playfully at every exit

You can tell Aston was tasked with creating as much light between the DB11 and Vantage as possible. A process that’s successful in some areas, less so in others. The steering, for example, isn’t brimming with natural feel, but on a level with the 488 Pista for reaction time – sneeze on the straights at your peril. I rather like it, as it forces you to employ an economy of wrist movement for maximum effect, but others were less sure. The interior too, has been distanced from the DB11, but without massive success. Quality is higher than in the past, but the spray of buttons manages to be both confusing to use and a little low-rent to look at.

By contrast, the BMW is unapologetically straightforward and doesn’t feel remotely special once you’re strapped in and those wheelarches are out of sight. That changes the first time you point it at a corner. It’s on your side from the get-go, more keyed into the road than the standard M2, immediately massaging your confidence. I judge this phenomenon by how quickly I kill the traction control completely, and after half a lap it’s off and I’m sliding it around everywhere like a loon.

In the Vantage, that trust and bond takes longer because the limits are so much higher. You’ve got the grunt to unstick the rears whenever you want, but it snaps a bit more abruptly, the traction control cuts in harder, it all happens at higher speeds. With everything off, I’m more aware of my mortality than in the BMW; with the electronics on, the Aston feels muzzled.

And then it starts to rain. Initially, I consider throwing both key fobs into the nearest bush and retiring for an early baguette, but, after a mild word with myself, I realise it’s a blessing in disguise. It lowers the stakes, lets me access the car’s breakaway characteristics and really explore a world over the limit. The M2 fizzes with energy, hopping off kerbs, jinking through the chicane, lighting up its tyres playfully at every exit. I’d like to say I’d have the manual, the purists’ choice, but I wouldn’t – the twin-clutch is just so good I don’t miss it, and I’m glad to keep both hands on the wheel. It’s good news for the Vantage, too; it might be a heavy car, but in the wet its balance is bob-on, and I start to appreciate the subtleties of its handling, the way it works all four tyres, the precision of the front end and the reliability of the brakes. The key, I find, is to keep everything as smooth as possible, trust the chassis, don’t poke the beast, relax and let it do its thing.

So why is it that I keep going back to the BMW? Because while the thought of one more lap in the M2 feels like a treat, in the Aston it’s tinged with risk. The M2 might be angrier, sharper and more dialled in than before, but it’s still got softer edges and a more approachable demeanour. Ignore the Aston’s all-encompassing powertrain for a moment, concentrate hard and you can spot flashes of genius in its DNA – a depth of thought and understanding of how to make a car go fast and make the most of every component. But unlike greats of the past, its brilliance isn’t immediately apparent; you have to rummage around for it. Not necessarily a bad thing, of course, but noteworthy in this company. I like the Vantage, I love the idea of owning one, but really it’s the M2 that fills me with more joy, more of the time. Always have been a jeans and a T-shirt kind of a guy…

Stay tuned to TopGear.com this week for our Speed Week 2018 track tests. To see how we got down to the circuit, click here