I'm not a huge fan of side chains yet, but Bitcoin's Grandfather (Adam Back) and a couple of other notables participating in this thread have done a lot to convince me they won't be the end of the world and may ameliorate pressure to adopt Gavin's Bloatchain proposal.

Doc's economic attack via free options still worries me, but I have faith antifragility win out in the end.

OTOH, 20MB blocks would destroy TOR, etc. compatibility and poke holes in our beautifully small (defensible/diffuse/resilient) network, which is the vehicle for BTC's antifragility.

Sorry I can't be more specific and impressively techie!   

What's your take on the matter, old bean?