After a pair of trousers for commuting primarily (3 miles each way) and ideally for trail riding when its too cold for shorts, these seem to fit the bill, anything else I should look at?

Not a lot! Enduras do the job and are reasonably priced – the only others I’ve seen similar are Gore – they do a few different ones. Like Endura, plenty of colour choices. If you like black. Or, er, black.
I’ve just ordered some Pearl Izumi soft shell trousers for when it’s really cold – have always worn Enduras before, but they have no stretch, so it’ll be interesting to see if the PI are more comfortable for riding.

Keela roadrunners.

by far the best cycling trousers I have ever owned.

http://www.keela.co.uk/roadrunner-trousers.html

Not what you asked, but I am really enjoying running knee length socks instead of trousers. I picked up the Madison DWR and waterproof trousers and found both too hot to ride in, even when riding in snow in south wales in December.

So far with long socks tucked into knee pads for MTB rides I am liking it, I have the 7 protection long ones, they have a thicker shin section which helps keep the chill and brash off the legs. They are also only £15 a pair instead of £80 upwards for trousers!

ton –
Keela roadrunners

They look good – will have to give them a try if the Pearl Izumis don’t work out.
(Nice colour choices too 😉 )

Is it worth considering tights ?
Not the bib type ..but the pull up fleece lined type ..with grippers
I have some Endura’s which I bought back in October ..not specifically waterproof but funnily enough when wet seem to work like a wet suit with the water acting as an insulating layer..
This was fully tested last Saturday in The Cheviots when crossing a stream in spate ..too deep to ride through but having got the bike over I then leapt like a salmon completely missing the far bank and went up to my nacky noo noos in freezing water..however within a matter of minutes my legs were warm once riding again
I am however still waiting for something(s) to reappear from whence they originally came ..

Already own two pairs of castelli tights, trousers more convenient for the short commute. If its just water hitting tights, then they dry pretty quickly, throw mud in there and they stay damp/cold.

Madison Zenith also worth looking at.

I got some in December, have been good so far. Only them for trail riding and not had any overheating problems, not being properly waterproof helps. Makes getting changed after getting clarted easier too.

http://www.pearlizumi.co.uk/men-s-escape-softshell-pant

Best item of riding clothing I’ve bought in ages. So comfortable and warm. Reasonable at £40 too

I have occasionally used my UnderArmour ‘ColdGear’ Golf trousers. Sort of soft-shell, bead water fairly well and quite stretchy.

Theses get some good reviews
https://www.ion-products.com/bike/men/bikewear/outerwear/softshell-pants-shelter/

Another vote for the Keela Roadrunners here

Be ready for the button to fall off in washer and a replacement need to be sown on.