I can't speak for all Renault garages/workshops but the three I have had dealings with have all delivered a high level of service.
I have had extensive dealings with
Renault customer services
as well since my purchase of my 05 Scenic II and have found them for the most part to be very helpful and over the last 3 years have seen a vast improvement in their standard of responses to customer after sales service.
I think it is pot luck with service departments irrespective of the marque some I have dealt with over the years have been dire to say the least.
Maybe the credit crunch will make manufacturers up their game as they have to chase sales and business for their dealers workshops.
Clio is a good seller on the used market in all it's variants