I have never tried a Brompton, but I do own a Mezzo D9.. I've looked at many reviews and many videos showing the ease of which Bromptons fold and unfold.. Here's my take on it.. In terms of more compact fold, there's no question the Brompton wins over the Mezzo, however, there's only about 10cm in it. And the Mezzo still qualifies to go on planes and trains (in the UK at least) so I don't see any problem with the fold not being as compact as the Brompton.

Now when it comes to folding and unfolding.. it's a mixed bag with the Mezzo... although it unfolds VERY QUICK compared to the Brompton thanks to its automatically locking catches (check out the "tie your shoe-laces faster" challenge videos on YouTube)... folding down is a completely different matter, and this is where I find the big difference between Mezzo and Brompton lies.. The Mezzo fold down is more complicated with more steps, and it doesn't seem to stay together naturally like Bromptons do.. I'm a new owner, so it may just be a case of gaining more experience to the "technique" but for me, it just doesn't look as easy as a Brompton fold and neither does it stay together very well unless you take extra measures.. there is a bar on the front wheel mudguard which is supposed to click into a slot which holds the fold together... for me, it's a bugger to get that bar in the slot and even if you do manage it, it doesn't seem to want to stay there.. what I do instead is hang the bar above the derailleur. That seems a quicker and more secure way to keep the fold together to me.

Saying all that, my bike is 18 months old and it's possible something has become misaligned and perhaps new bikes don't have this issue. I'd be interested to know other owners experiences.

One last thing..when comparing the Brompton with the Mezzo for fold size and compactness, you have to take into account that the Mezzo has a non-folding mainframe and better designed handlebars than the Brompton which provides an all-together superior ride to the Brompton in many ways..in terms of stability, better steering, better efficiency, better comfort etc..this is what I've seen said over and over on many reviews. So I think there is a clear trade-off on the Mezzo, and really it's a very good trade-off..for 10cm loss of compactness on the folded size you gain all that.

There's no doubt that whilst the Brompton is a superb piece of engineering which focused on providing the most compact bike and ease of use, the Mezzo is a superb piece of engineering that aims to provide the best of everything without compromise.