Well, that assumes that the advance itself is small. I guess whether it's worthwhile is in the eye of the person who purchased it. Many have upgraded a processor, memory, CPU cooling, from 32bit to 64bit only to find that it really didn't make a noticeable change. The SSD on the other hand, does make a change, it's quantifiable. You can measure things with a stopwatch and see without a doubt it's faster.
When you already have a HDD drive doing the exact same function only milliseconds of difference which add up too not much over a week.
If your talking about boot time then ''why don't you go and make yourself a cup of tea whilst the computer boots up like most people do''! Or, just leave it on.
It's not just about boot times. While these do improve, there are other beneficial areas as well.
#1). I don't bother hibernating my laptop anymore, I simply reboot it because it's fast
#2). A malwarebytes scan of my entire laptop takes 2:30 and scans 230,000 items
#3). My laptop is now silent, no more clicking and clacking from the hard drive
#4). A game that used to take 20 seconds to get to the menu and another 25 seconds to get into game now takes about 8 seconds total and I'm playing.
#5). My Windows XP Mode VM (where I test most things), boots and is at desktop in just 11 seconds.
£85 not worth it. £30 I'll consider it but there are disadvantages that I have pointed out before.
I don't think I have anything more to say on the subject.
Money is always the key. Whether it's worth it to you, only you can decide.
I used to poo-poo SSD's as well when they first came out and didn't feel like they were worth it. I finally decided to get one, simply to see what all of the fuss was about (I do computer work for a living, so some of the cost went towards educating myself)...and I'm glad that I bought it. No regrets. I now have one in my work laptop as well...was even willing to go from a 160GB mechanical to an 80GB SSD and simply have less on the computer for the speed advantages. No regrets on that choice either.
I'm not at a point where I consider the SSD a "must have" for any computer. But it's certainly a "want to have" on my powerhouse boxes that I consider high end performers.