While i don't prescribe wholeheartedly to the McNamara fallacy of the published numbers, i might prescribe to the marketing because i think the tubes are quite different... ive built ~50 bikes, 90% from colombus tubes, and my 2c is that OMNICHROM is definitely different stuff from the 25CrMo4;

It sounds different, it feels different to work, it builds into a bike that feels different to ride
(the tube shapes are also often different, so buckets of salt, though im fairly consistent when choosing diameters)

id like to think the omnochrom bikes 'zing' a little bit more on hard tyres, and they have a more likely whippynes in their feel when handled well at high speed, this means they can wallow around a bit in rough/slow surfaces. and REALLY dont descend well without enough weight on the front wheel.

with my personal bikes, id say the zona bikes accelerate well to 40kph. the life bikes accelerate well from 40kph.

I like to use life for flat-out smooth-surface race bikes for fast & light people (road bikes with road bike brakes, velodrome bikes), and in the top half of bike one step more grippy than that, eg a very sprinty road rider might get a life tt/ss and a BIG zona dt/cs.

I definitely found omnichrom tubes more difficult to work with than the 25CrMo4 early in the peace; i buckled a couple of tubes cold setting mistakes very early on, and cracked a chainstay after crimping it too far. i quickly found a fondness for zona that lasted for the next ~30 frames.

If i'm going to be doing any bending/pressing/squashing tubes nowdays (e.g. i have a fondness for a /quite squished/ flat top tube that tapers back to round at the seat tube) i buy the zona tube. i think they take a set more readily, and this lets me go deeper when forming, to get the shape i want after springback, without such extreme forces and shapes occurring along the way.