Jimbob-80.
Dont get me wrong i love the astra and for i use it for it's great on the motorway.
The 172 mk2 clio we have is great. As far as been unreliable my astra has cost x3 times as much in repair bills to what the clio has cost us. The power delivery is great and you can drive very steady in day in day out then drop it and it really shifts. puts a smile on my face every time i drive it.
I dont know if i could drive it day in day on a mway though. MPG is good on it too average or around 35-38. They do torque steer alot in lower gears and at the end of the day they are french, so you do get some annoying rattles and overall feel does not feel as solid as the astra.
One of the biggest problems is the standard exhausts falls to bits and they are v-expensive to replace OEM ones but a decent cat back system is around £300.
We are just in the process of having the aux belt & cam belt done. No one wants to do it as they are a right nightmare to change.
I would make sure that that is done if you are buying one.
My best advice is take one for a test drive, see what you think yourself.
Hope thats helped.