I have a DeDietrich which allows me to combine 2 zones.
I use it for a large Circulon frying pan I have and also a large "family" pot when I do a 24 portion chilli etc for batch cooking.
It allows me to combine the front and back "ring" on both sides and I love it. Had it for over 3 years.
There was a huge thread about induction hobs on the property/DIY board if you want to read up on just the induction part. General opinion was they are great, easy to control, easy to clean. But you do get what you pay for. Lower priced ones can't cope with all 4 rings being used without some loss of power.