Can vouch for the Roxy
In fact this year the Roxy is the host for the International DeHavilland Assoc annual dinner and all around pissup! All rag and bag devotees can attend, subject to ticket availability. I'll be there, but Jaba probably won't want to go though - he'll most likely be attending some Retard Vehicle aluminium symposium.
Anyone looking for accom - large private house on the lake, mostly an all aussie turnout of tenants. Walking distance to the show, pool,no shortage of beer fridges. About $60-$65US night, and if you're nice, washing can be done, basic brekky provided, and transport for inebriated visitors can often be arranged. Let me know (usual disclaimers).
All previous tips are good. I've particularly enjoyed attending some of the workshops and lectures. Certainly join the EAA before going - membership entitles you to free admission to the museum (a full day if you get up late).
I generally buy/beg a lightweight walking stick'folding chair, which I either lose or redonate to the cause - invaluable for watching the afternoon airshow.