What is the deal with SL55 AMG

[blau]

I have been looking for a SL for a while, more of the SL500. because I have been taught never to buy a use turbo (Super charger too).

However recently in my area I seen SL55 being advertised for only a few thousand more than the SL500 some even at what appears to be the same price. Seem like the 55's are a value.

What is the deal with these 55's. Are they problematic? Am I buying into trouble if I buy a 55 instead of a regular 500.

What do you guys think??

thanks