From what I've read, blocksize increase has 2 downsides. For one, it's a temporary solution. Raise the blocks today, the raise them a little more tomorrow, and before long, they are HUGE. Second, it centralizes the community of nodes. If they get too big, only certain wealthy individuals can run nodes and thus, you have kind of defeated the purpose of a decentralized currency.
That being said, I am really into the Lightning Network lately. Off-chain tx's that only need to be resolved on-chain when there is dispute. This would allow for smaller tx fee's, faster (instant) confirmations, and potentially millions of tx's per second. It would also unbloat the blockchain.
RE: Bitcoin Hardfork called off #NO2X !!!!