How much temporary or interim storage space do you need? An SSD is good for running the OS and programs but not reliable enough for long-term data storage.
Uh, what? SSDs are very reliable. Any name brand SSD out there will outlast the computers useful life in most typical end user usage scenarios. Sure, there are exceptions, and anything can fail any time, but a mechanical HDD is far more likely to fail than an SSD overall. Plus, even if your statement was true (and it absolutely isn't true), the increase in performance and productivity would be a worthy tradeoff.
I've worked with computers since I was in middle school, worked full-time repairing and refurbishing all makes and models of laptops and desktops for 7 years, and now do IT consulting/computer repair work of my own. Also managed a small datacenter from top to bottom for about a year before they sold the building to a high school. I've used everything from dirt cheap consumer grade stuff to high end enterprise drives. Over the course of all this, if we exclude some really cheap and nasty generic SSDs off Amazon that died within a couple months,or the early SSDs from OCZ that dropped like flies for a few years, I can count on one hand the number of SSDs I've replaced. While I've replaced hundreds of mechanical hard drives, of all ages. Some last a week some last 60,000 hours. You never know.
Especially in a laptop that gets moved around when on or handled roughly while powered off, you're at far higher failure risk with an HDD vs an SSD.
When I left my laptop on the hood of my car many years ago and drove off in the night and found it 5 hours later having been run over by all sorts of cars and semis in that time, well, neither my primary SSD or secondary HDD survived. But, that's what backups are for. No matter what kind of computer, drive, etc. you have, a good multi-tier backup strategy is the only way to keep your data secure.
Replacing your hard drive with a solid state drive and/or buying an SSD-powered computer is the #1 best thing ever. Every time I have to use a clients computer that still uses spinning rust I am reminded of this. Every time a client complains their computer is slow, the first thing I do is see what the storage medium is. Well, usually it's a mechanical hard drive that's at 100% disk I/O just because Windows Update is running and the computer is literally unusable for an hour, and they get frustrated and turn it off before it can finish so it's always doing its thing in the background... Swapping it out for an SSD for $100 or less in most cases, is the answer. Sure one can spend hours trying to tweak Windows or the background services or do all sorts of weird hacks or upgrade the RAM or whatever but at the end of the day the days of mechanical hard drives as boot drives are over. Even if you store a bunch of stuff on your machine locally, a 2TB SSD is only about $200. It's rare anyone would need more space than that, but if you do, there are many options... external hard drives, secondary hard drives if it's a workstation class laptop or a desktop PC, a NAS, cloud storage, etc.
Really moving forward the only use case for spinners is going to be NAS/server environments... most stuff in small business or home networking is still connected via Gigabit ethernet so SSDs are pointless there. Although with Multi-Gig or 10Gb networking becoming more and more popular we'll see a shift here too.
I'm just so happy that finally SSDs are standard in most systems, even cheap ones. Saw an i3, 4GB RAM, 128GB SSD, Asus laptop with 1080P/full HD screen, backlit keyboard, for $249 at Staples last week. Sure, that isn't a ton of space, but it's still going to be faster in day-to-day usage than the laptops that were the norm before even if it was a "better" system with an i7, 16GB of RAM, and, ick, a 1TB 5400RPM HDD.
