Ibra is massively underrated in England. Perhaps he is slightly overrated in Italy and Sweden but I do think his record speaks for itself.
2002: 1st in Eredivisie with Ajax
2003: 2nd in Eredivisie with Ajax
2004: 1st in Eredivisie with Ajax
2005: 1st in Serie A with Juve (titel later revoked due to Calciopoli)
2006: 1st in Serie A with Juve (titel later revoked due to Calciopoli)
2007: 1st in Serie A with Inter
2008: 1st in Serie A with Inter
2009: 1st in Serie A with Inter
2010: 1st in La liga with Barca
2011: 1st in Serie A with Milan
He's played a integral role in all those wins and has in many years arguably been the most important player on the team.
He hasn't been as succesful in the Champions however, but he's definitely not a CL-choker as is often suggested by English pundits.
The only problem with Ibra is that he's 29 already and with the style of play he has I can only see him play top football for another 3-4 years.