Hello,
There is no rules, it depends on products and periods.
I can talk only for France.
For me according to the periods Shopzilla and Shopalike had good results in addition to Leguide, for cons Cherchons I have never done anything remarkable.
Twenga a lot of traffic but unprofitable smoothed over the year (between beautiful and catastrophic periods), you really have to follow.
But above all, the most profitable and the biggest potential is ... Google Shopping, which takes more and more shares.