I seek advice.
My parents would like to replace their 2009 iMac with another iMac. They would like to get a 27 inch. I think the Retina isn't worth the extra few hundred dollars and I doubt they'd appreciate the display. Do you think now is a bad time to upgrade to a regular 27 inch?
Here's the advice I always give about "buying now" vs waiting for an update on hardware:
It's a gamble.
On the one hand, sure you may wait until update time and get more bang for your buck, updated processors, more ram, new design etc. you can sometimes win.
Other times you might "lose". For example I was waiting for an update to the iMacs in mid 2013, while the late 2012 had been out for like 9 months. I needed a computer and I have a few weeks until some announcement passed just in case (even "analysts" we're predicting an update). It never came so I just bought it.
A month or two later my model was updated. What happened? They introusced haswell architecture (unimportant for the large part for a desktop as the gains are mostly in low power usage) and they dropped the discrete graphics card for my model. Sure thrn in built is "comparable", but I always like the robustness of a discrete card.
In this way I sort of "won" by just getting what I needed. People should just consider the value of what is out now and the price. For people like yor parents, they'd never know any difference between current model and any processor or storage bump. Sure they may introduce new features that you'd miss out on but like I said that's the gamble. The best update I could see them doing is introducing fusion drive as standard.
Another thing about waiting is that it might not actually happen. I expected updates to come in October but only the retina surfaced. So if you were waiting then you'd still be waiting now. Another disadvantage is that here in NZ, the price of macs is dependent on the current exchange rate. When the retina dropped, it updated the prices of the entire Mac line and they all became more experience
Without actually changing. So at least here, it was a bad move to "wait".
Lastly, there are most definitely "bad" models or generations of macs. By getting anew update you CAN be a sort of early adopter for a new tech. Older ones have at least been out for 6-9 months and have a better chance at having issues surface and be known and ether corrected or reported.
Of course nothing is ever certain or 100%, but just things to consider.