I wasn't in this car for very long (only Sept to Dec) but covered 4,000 miles in that time, and was pleasantly surprised.
I had the choice of this or one of the new Zafiras, but chose the Meriva as both were 1.6 engines and I thought the Zafira might be a bit slow.
At first I wasn't sure about Merivas, you don't see many around, and they look a bit dumpy, but I found the comfort levels generally good, (shame there's no tilt adjust on the steering wheel though), and the 1.6 engine gave better performance than I expected, being smooth and revving freely, but turning over at low revs at cruising speed due to longish gearing.
The handling was so-so, I know they get good write ups in the motoring press, but I found the steering pretty vague, plenty of roll in the bends and if you entered a bend quickly and then braked sharply, the back end actually kicks out a bit, making it feel unstable. Also crosswinds tended to catch it out as well.
The interior is dull, but functional, roomy for passengers, but the boot isn't as big as you'd expect for a car that encroaches on basic Focus c-Max and Renault Scenic pricing.
Would I put my own money into one-no, probably not, I'd buy a Picasso which is bigger, the same price and has a lot more about it, but I wouldn't blame anyone for going the Meriva route.