Yes. It was. I decided as much right about the point I slotted the 635 in next to the M635 in the office car park and got out to admire my handiwork. Crikey, they looked good. And all the more so on the way out to our photo location. Call me a child, but tonking along in my car while catching glances of the smouldering nose of the M car staring me out in the rear-view mirror on the way there. I couldn't help but feel a huge swell of pride imagining how good our little convoy looked.
On first acquaintance, the answer has to be 'yes'. Even at slow speeds, the 286hp 3.5-litre six-pot of the M car feels more aggressive, with a coarser engine note and a keener response to the throttle; open the taps fully, and the intoxicating metallic snarl of a thoroughbred straight six fills the cabin as the revs pile on. For such a big, heavy car, the way the M635 moves is fabulous; an exponential surge of forward thrust that dares you to hold it in gear just a little longer, all the time.
Jump into the standard 6 straight away, and the difference in character is noticeable. It feels lazier and less crisp, and at first, that's an irritation; you long for the crazed yowl of the motorsport-bred M88/3. But as the miles roll by, its charms reveal themselves. It's happier at this laid-back pace; content to move along briskly, making good use of its mid-range torque with the odd excursion to the red line just for the hell of it.
The gulf between these two cars' characters, however, narrows once you hit the twisty bits. Of course, the M635 has the stiffer suspension of the two; its ride is a touch less pliant, but the payoff is that it doesn't roll as much. That said, there's still plenty of give in the suspension; combined with the same slow, deliberate steering and big, thin-rimmed wheel, the result is that the differences aren't as noticeable here as they are in a straight line. What you do get with the M car, of course, is the ability to slide the tail wide just as you please; the 635's standard slushbox makes that nigh-on impossible unless the roads are greasy - despite the fact it's fitted with the same limited-slip differential.
I said at the start that this could go one of two ways; happily, as it turns out, there's a third one. I met a hero, and it gave me goosebumps. You can't ask more from it than that. And yet I didn't come away disappointed with my own faithful old shark. Maybe I'm biased, and making excuses for my own car - you'd be within your rights to think that. All I know is that, driving home, I didn't feel disappointed. In fact, I was grateful for its effortlessness; for the big wave of torque its auto 'box kicked down to and surfed upon as I powered past a dawdling Honda Jazz on the back roads. Where the M635CSi is a classic supercar masquerading as a grand tourer, the 635CSi is a laid-back cruiser with a sporting edge. Which, quite frankly, is exactly what I want it to be.
Car: 1988 BMW 635CSi Auto 'Highline'
Run by: Alex Robbins
Bought: December 2014
Mileage at purchase: 100,895
Mileage now: 107,928
Last few months at a glance: A drive in an M635CSi doesn't leave our 635CSi feeling like the poor relation - thankfully.