Obviously you need to defend your purchase in your own mind. And that's fair enough.
Actually, I have neither a need
nor a desire to defend to my purchase. I made the purchase because I thought it was worth it and I still do. I was simply responding to someone else's misinformation.
But is it a waste of money, depends on the person clearly.
So what do we disagree about, really? I'll go along with that. The comment I took objection with and responded to was "the extra $300 is a waste of money". There were no qualifications made by the person I took issue with.
For you it was worth it. For real tangible reasons, I would say it is not worth it.
Not worth if for
you, right? Because if not, please make up your mind about it depending on the person.
Otherwise use that $300 and buy an SSD, for sure you will notice the difference more.
How are you going to install an SSD in your iMac? Are you going to do it yourself? Are you going to risk voiding the warranty by disassembling (not an easy job)? Are you going to replace the internal HD with it? Since the internal HD has a thermal sensor are you going to short it since it will no longer serve a purpose and plays a part in controlling fan speeds? Or will you remove the Superdrive and install it there?
Also I think most people DON'T use any video compression software in their day to day computing, once off or once a year would be the most common usage pattern. So waiting a few more minutes to get the job done is hardly worth the upfront $$$.
Again, to
you. Video encoding is not the only advantage of the i7. For me, Hyperthreading alone made it worth the extra $200 to upgrade. HT lets your system run extra threads per processor. The Core i7 system has 4 actual cores and 4 'virtual' cores. At the moment, very few programs can take advantage of these 4 'virtual' cores, but in the near future HT use will easily become common, especially for heavy duty apps.
It's just futureproofing and like I said, if you plan on using your machine for the longest time possible there's no reason not to get the i7.
However, like you said, in the end it's all about what YOU need. To say it is a "waste" in all cases is BS and that's all I was saying.