Basically I am saying what Kevin Wyndham said, just added a bit of fluff.
A sad day occurred in late 2011, the best laptop ever made was no longer, I had to get my 2009 version replaced so I could continue to be in my happy development place.
The Laptop is the MacBookPro 17 inch i7 2.4GHz, a most suitable machine to upgrade and do every single task I could ever throw at it (her, sorry can’t help but anthropomorphize).
I managed to take the machine all over the world, working in some funky places, never missing a single beat.
Then 5 years into use the screen went wonky, and I found out about the graphic issue.
I took it to an apple store in a country that the machine did not originate hoping to get it fixed for free.
But…, ooppss, sorry there is a happy ending, it was fixed in next to no time, and YAY!!! for free, cost nada.
Therefore I now have as close to a brand new laptop as I might imagine, on inspection it is as sparkling as day 1.
I invested in a Samsung 1TB EVO 850 PRO SSD, plus 750GB hard drive in the DVD bay and 16GB RAM.
The result for me is a machine that is very quick in all ways I operate, it is unlikely to be significantly overhauled by many generally available laptops for some significant time, not bad for a 6 year old machine with( I hope) at least another 6 years of life.
In my own mind it seems that many currently available hardware solutions are now in advance of the software used by the majority of people, both consumer and more technical users, not how it was only 10 years ago.
I am not likely to benefit, possible as many programmer/developers, from small increases in processing speed or slower jumps in architecture ability, that has been seen in the last 5 years.
If my machine were 10 times faster I would suspect it unlikely to make much difference to my work throughput.
Back to the original post, as suggested by others, the absolute speed of the processor is unlikely to be arbiter, SSD, good graphics card with its own ram etc is probably more likely to show real life speed improvement.
Having gone through the process that Jeff is doing now, my end solution was as described above, no need to change the computer, it (she!) is still more than capable to do the job that I continue to do(and still looks shiny!).