Solutions is not ideal but in a credit crunch a bird in the hand is worth two in the cage. People from ACN have gone on to hold good positions at other consultancies, Equities divisions in IB, Telco operators and other FTSE 100 top companies. The majority of these ex ACNers have been consulting but some have been solutions.
The real truth is in Solutions, you get what you negotiate so if you let them offer you a low package then they will.
If you want to move on to better things then I would not stay more than 3.5 years with ACN.