Yep, same tyres on my 19's. I think they use the same on the 17's but with a different profile.
They are fine. The ride maybe a little harsh when it comes to rougher roads but that's the only time you will tell a difference between the 2 tyres in terms of harshness.
In terms of handling, I had the prem for an hours test drive when I was looking but drove back the same route today and noticed there was less body roll and a firmer ride but also more confident in taking the corner at a higher speed.
I do appreciate the comments regarding kerbing "issues", however I drove for years with 17's on my BTCC style Primera (must have covered around 60,000 miles on those wheels!), with tyres which were slightly less taller than what are on the QQ and never had an issue, however you do become acutely aware of what's around your tyres at all times (can only be a good thing really!). What you could find however (although yet to experience it), it is easier to cause a blow out, or damage a tyre/wheel with low profile tyres taking a decent sized pot hole at speed. Saying that, you should avoid kerbing your tyre anyway as it can result in unseen damage to the tyre wall increasing the likleyhood of a blowout!
Go for 19's if:
You like them
You have been previously good in other cars with lack of kerbing
You live in an area where generally the roads you take are well maintained
You don't the trade off between slight increase in cornering ability and slight loss of "give" on rougher roads
Go for the 17's if:
You like them / If you don't like the 19's style
You tend to bounce your car up/down/sidewalls off kerbs (you should really avoid doing this, not only could it damage the tyre and alloy, but it can really screw up your suspension and steering components!)
You live in an area with roads which are poorly maintained
You prefer comfort and have no need for the additional grip level that lower profile tyres offer.
Want lower maintenance costs in terms of replacement tyres.