I think the "massive alloys" AKA low profile tyres will do your head in ,and your back over 75K 3 years compared to the comfy motorised armchair that is the Omega
i quite like astras though we.ve 5 in the family
First thing I did with the 3.2 was swap the wheels 18 -17,, or was it 17 - 16, anyway it made for a more comfortable ride. I hate the ride in the Mondeo, wheels are too big, but I'm too mean to buy smaller as fitted to poverty spec models. Omega wheels plus tyres were readily avlbl back in the day. First thing the 3.2 buyer did was swap them back! Each to his own.
Next car will be chosen solely on comfort, so recommendations from other old farts considered.
Some 'performance' models have bigger brakes and smaller wheels won't fit.
I vaguely recall Ford making noises about fitting 14" wheels on the facelift Sierra, and again jumping from 14"-15" on the Mk2 Mundeo and again to 16" on the Mk3 Mundeo in order to accommodate the larger brakes.
Conversely, all Omegas can use a 15" wheel.
Mercedes had 16" as a standard wheel diameter, increasing disc thickness and using four pot fixed calipers (as opposed to bulkier floating ones) to uprate the brakes for bigger engines. The wheel width being the only real variation.
Certainly any increases in wheel size from one generation to the next was necessitated by an increase in brake size rather than for styling purposes.