Disadvantages
If the opening bid of 2♣ is exclusively used for strong hands, the auction becomes more susceptive to disruptive (jump) overcalls (especially when the opposing partnership is not vulnerable) than the "old" treatment of strong two bids. However, that danger is smaller when compared to strong 1♣ system in strong club systems, because 2♣ bid is made with bigger high-card strength and on a higher level. On the other hand, the strong 2♣ opening reduces the bidding space for the pair themselves compared with strong 1♣—sometimes, the pair can be unable to find a fit on a relatively low level (below 3NT), and/or reduce the space for effective slam investigation with cue bidding.
Read more about this topic: Strong Two Clubs