Leinster and Munster are among the best sides in Europe, Ulster can beat anyone on a given day, as can Glasgow but neither are consistent enough to challenge for European honours, Ulster did win the Euro pot some time ago though.
The Welsh sides go through cycles, Ospreys and Scarlets tend to be the better teams of the four, Benetton are a tough side at home but don't travel well at all,
Zebre tend to get battered away and struggle against the best sides at home too.
My team Edinburgh are rubbish, but we start every season with hope, we've lost two B&I Lions this season, it will have an impact.