My experience on this:

On purchases, no way
I bought my iMac, just to find out two weeks later the new refresh was out. Went back to the store that sold me, they said no way - This is at @atsc ikano

My auntie bought the iMac one day before the new refresh coming out. By this time, every one knew the new specs are coming out. Machines still sold the thing to her, full price, when I heard about it went back to Machines, they say they will only take back at resale value. I would not have been pissed if they sold the thing at a discount price. This was full price. To make matters worse, the new iMacs were sold at a slightly lower price. This is at Machines Mid Valley

But, in terms of support, its excellent
Bought an U2 ipod from Singapore, somehow got soaked in water, actually sent in for repairs, the fellow at atsc said since on warranty got me a brand new one. Then that unit went busted after few months. By then U2 one was no longer available, they upgraded the iPod. This is at @atsc ikano. The best part, I was hassled with paperworks, receipts and stuff like that...

that time still noob, didn't know about macrumors website. plus i wasn't expecting much on my case, just trying my luck

but for my auntie's case i think machines should have at least said something, she just went there saw it was nice and just bought it and she bought two imac and one macbook air, and for someone who was doing a large purchase, they should have had some ethics in selling. at that time everybody new the new one was coming on that day..unless machines had no idea which i highly doubt so....and my aunt only called me after she bought it and she was so happy that the fellow who sold it just threw in two keyboard protectors, i told her, you just got ripped off.....