They stop you adequately and are pleasing to the eye . I have had a few pairs of this style of brake . I always preferred the cam quick release on the caliper which monoplanes brakes lack . Also Campagnolo missed a trick by only catering for the racing crowd with tight clearances unsuitable for the more modern view of wider tyres and more clearance . Having said that I have Campag cantilever brakes withy tons of clearance .
The advanage of the QR on the lever is that if the brake is left "un-set", i.e. "released" the bite point of the brake relative to the bars is unchanged.
You don't see it now because of disc brake but at one time you'd see riders either reach behind at the bottom of a climb to flick the QR off, so that if the wheel flexed under out of the saddle climbing loads, it wouldn't rub on the brake blocks (as often times back then, climbing wheels were exceedingly light and so under high torques, twisted enough for that to be an issue) or the Campag riders, thumb the button across.
They would have reset the QR at the top of the col so that they had good braking on the descent - when radios first came into the pro peloton, it was a common thing to remind riders to do the reset.
With Campag's lever based system, it didn't much matter if they did or didn't, in the sense of braking efficiency, it only mattered for feel. The very first ErgoPower levers actually auto-reset the first time the brake lever was pulled back but Campagnolo took the spring mechanism out that actuated the auto reset very early on, as an unecessary complication. IIRC it was done as a running change in mid-late 1993.
I don't think it's far it say that any brake makers "missed a trick" on wider rims and tyres - at this time, no-one was talking about the benefits of wider rim / tyre combinations, in fact the trend was towards minimising footprint and rolling resistance - Monoplanar and most of the subsequent designs long predate even c15 rims ... most rims when Monoplanar was developed were c13 or sprints with an over brake surface dimension of 20 - 21mm and typical tyre widths were 21-23mm, 25 or (very radically) 28 for races like Paris Roubaix. The problem was often not that the brakes couldn't accommodate the tyre - but that the frame couldn't. I have a couple of Pinarello Dogmas from 2009 where anything bigger than 25c won't go under the fork crown, no matter what brake I fit ...