But are some created more equal than others???

I’ve had a new tap in the kitchen and the hot water flows out of the new ‘un a lot slower than it did out of old ‘un. Any theories why?

Because taps have different valving strategies, differing seal materials (cheap taps can have seals that swell and block the flow as they heat up) and some are just badly designed. Much like bikes, you can buy tat, you can buy tat dressed as bling, you can buy great stuff cheap and you can buy expensive stuff that’s great.

is the service valve opened properly?

There are also different spec taps to suit differing system pressures, so it may be that you have a low mains pressure and your new tap is for higher mains pressure?

I am no plumber though.

What slack says – check to see what the minimum pressure the tap will operate at.

Is there an aerator in the end? Try unscrewing the nozzle if there is one and see if there is a plastic part with holes in. We had one in ours which I took out to get proper flow back.

From Wikipedia
A faucet aerator (or tap aereator) is often found at the tip of modern indoor water faucets. Without an aerator, water usually flows out of a faucet as one big stream. An aerator spreads this stream into many little droplets. This helps save water and reduce splashing.

Andy