City trousers
I have the City trousers and have had the summer trousers too.
For the UK, i generally wear the city trousers due to it being cooler here. If i was touring in warmer climes and stopping for lunch etc the Summer ones are really good as you can slip yer boots off, zip the legs off, unpack your flip flops and sit and have lunch in relative normality. Neither are waterproof, so if you are going to use them as everyday trousers, you will need some overtrousers.
The thing i really like about both, is that they have cargo pockets, which are sooooo much more useful than normal pockets!
You pays your many, you take your choice