the intermix sale is like the barney's sale in that it's all the stuff that they didn't sell during the season compiled in one place. though it's definitely not as crazy (in terms of crowd/security) as barney's. it's almost always at metropolitan pavillion which is on 6th b/t 18th & 19th.
like all sales it's hit or miss. my general strategy when dealing with these types of sales is to have a mental list of things i wanted during the season but didn't get mainly b/c i couldn't afford them. the really great thing is that they compile all the stock from their stores across the country so you have a better shot at getting certain things. the downside is that the first day there's usually not that much of a discount in relation to regular sale prices. i think when i went last summer it was like 10% or 20% off the ticket price. which is okay, but again the main advantage is possibly scoring something that you wanted but couldn't find in nyc. they usually have a decent stock of jeans, and a lot of the house label. which i personally like for work clothes. i picked up a really great pair of house label crop pants 2 years ago that i love and they were like $40.
i've always managed to pick up stuff that i like. when i went to the sale over the summer i got some great deals on hollywould & kors sandals. i really wanted the stella espadrilles, but when i went back they were gone. my general strategy is to make a list of things i want ahead of time and to hunt them down. then i just look around to see if there is anything else that catches my eye. in my dreams i hope that the chloe boots will be there, in my size, for less than 1/2 price though in reality that probably won't happen. i do however have my eye on some kors shoes.
lynnie -- they carry the same lines as the store... pretty much all your high end denim lines, and then some great mid-range designer pieces, see by chloe, sonia rykiel's (sp?) second line, stuff like that.