The survey are all different they ask screening questions first such as age, if you have children etc. they can be anything from what your child has for lunch to what you think of new movies.
I use one poll and each survey is normally 10-20p but they're really short so don't take much time. They don't pay out til £40 which takes me 2/3 months but I check for surveys several times a day. I'm currently on £29 so should get a payout soon. They only pay via PayPal or bank transfer though
Opinion world does them in points, normally 50-100 points per survey and they payout when you receive 1000 (I've done this in a week or 2) and you can choose from loads of vouchers with them, you get the voucher in the post a couple of days after you request it.