I got my first paramo when they first came out. '94 I think. Iirc cascada came out then alta which i got. When I got mine the aspira smock and salopettes for alpine, winter mountaineering and ski mountaineering had just come out. Early designs were not great with the ban on velcro causing he wide cuff fabric to fall out of the popper adjusted cuffs in a most annoying way. They did the job though and were cheap! I got trousers , jacket, a 200 weight fleece, silva type 4 compass and a base layer for about £200!
Apparently the actual idea was a guide based in the Lakes. He developed the design and prototypes with Nikwax coming in towards the end of that process. I met a guy who owns an outdoor shop for decades and knew the guy before it got taken on by Nick Brown. The early designs features I didn't like came from him I reckon. Anyway I stopped wearing paramo for 10 years or so because of the original designs and later fit / sizing.
In more modern times designs are light years better. Biggest improvement is fit. They have different fits from short, fat dog walker to athletic-ish slimmer fit in the mountaineering smock / jacket. If you like smocks there's 3 models and they fit differently too. There's also better design cuffs with velcro.
Fabric layers work by wicking or pumping sweat through the inner layer. That keeps moisture away from your skin but wetting out in heavy rain of the outer fabric can mean it doesn't dry out. Rain stops it does like a softshell. To me paramo is like a two layer softshell like rab vapour rise but better in that it resists rain longer. With trousers if you put your knee down to scramble up somewhere it will force water through and you'll feel the cold water on your skin. A heavy pack in rain can have the same effect where the straps are. Pressure forces water through.
Now my advice is to go to a premium retailer or an actual brand shop. You need to try them on. Don't go by advice of others, colour or design features. You want a good fit first. The only exception to this is certain use considerations. Velez adventure lite is an athletic-ish fit and unlike any of the other two velez versions in fit. Any lite versions of the paramo analogy isn't great 8n prolonged heavy rain but will dry quicker than the standard versions. That might suit of course.
If you doubt it then his about this for testimony? One winter wildcamping trip i fell through snow into a hidden tarn. Not far from the edge but I got wet halfway up my thigh.i got very cold, very quickly.i was wearing softshell trousers and a rab vapour ruse jacket. I pulled in behind a low outcrop to get out of the wind and put my ancient cascada trousers on. Then set off to the camp spot and actually back to nearer the cars. I was planning ti go home as I was suffering. Anyway 10 minutes later I realised my trousers underneath were dry. Wicking softshell trousers and paramo did it. I was warm except my hands that had got wet as well. Even my second boss couldn't warm the so I went home, so did everyone in the end.
In summer it is simply too not for active use. When I first got paramo I used a buffalo windshirt over a thin paramo fleece, mountain m shirt I think they called it. A predecessor to their system fleeces which work with their windproof tops to create effectively the analogy waterproof. The original fleece was reversible for warmth or cooling but not as good as current fleeces. Howgood enough for heavy summer rain with a windproof.
TL:DR
It's good but try the all out. Get one that fits. Sort out a summer/ warmer weather alternative. It's not perfect so consider your alternatives too. Opinions of others matter less than what you think having tried them on in the shop. You might like the idea but it might not work for you.