Here's how to tell if you are ready to take the plunge.
You prefer quality to quantity. The biggest knock against SSDs is that the cost per gigabyte. The easiest way to fix that is to know how much data you are currently using. Then add 15% to allow for some limited growth and swap space.
For example, if your notebook's 320GB hard drive is only 1/4 full - not uncommon for primarily business use - that's 80GB. Add 15% or 12GB to get to 92 and then round up from there to the next largest SSD. Instead of a 300+ GB SSD @ $300+ you'll be fine with a 120 at ≈$120.
Don't buy unless you plan to buy for all your systems. Once you get used to an SSD on one system all your other systems will seem maddeningly slow. Happened to me.
Battery life is a problem. Notebook drives are very power efficient and a small part of total notebook energy consumption - screens are much worse - but unless your sleep mode is very efficient you'll find that you're also chewing up battery life doing nothing.
SSD bootups are so fast that you won't mind shutting down for lunch - or booting up to check something for a couple of minutes. And an SSD will add 15%-20% to your battery's current life - not a strong reason to buy - but it helps.
You back up regularly. SSD reliability varies a lot by by brand. And even good brands have failures - which with SSDs tend to be sudden - that aren't preceeded by clicking noises. So back up your data regularly
You'll do it yourself. Install costs make an expensive proposition that much worse. SSDs are carefully made to install just like disks. But you also need to migrate data and that is trickier on Windows.
You use it for business. Your notebook will be noticeably snappier and you'll be happier. That should make it a no-brainer.
Here's why NOT to buy now. My friend Jim Handy of semiconductor research firm Objective Analysis notes that flash prices have
. . . been declining at a pretty steady 60% annual rate for a whole year now.
That means that today's $1/GB SSD will be next year's $0.40/GB SSD.
Which is the best reason I can think of to wait.
The Storage Bits take Don't obsess over performance numbers when comparing SSDs: they all do small I/Os so much better than disks that you'll love whatever you get.
If now isn't the right time for you, then wait a while. Prices will only get better.
Comments welcome, of course. My first notebook SSD cost $400 for 10MB back in the early 90s. Maybe that's why $1/GB sounds good!