SSDs and HDDs don't really differ in power consumption, but they do differ in time-to-complete. So depending on what you do most of the time, adding an SSD to increase battery life is a moot point. I haven't ever had reliability come in to question with a hard drive, and I've done some things that you shouldn't do. And HDDs don't add significant weight.
Let me add another reason from a typical consumer standpoint: space. If I was going to buy a laptop as a primary use computer, 128GB of space, regardless of its positives, is paltry compared to 500GB to 1TB that I could get on some other laptops. Sure, you could add an mSATA or PCIe based SSD, but those are ungodly expensive. The only happy medium are SSHDs, but these are only available in higher-end laptops.
And if you're going to ask me to use the cloud for additional space: no cloud storage service will hold what I want to store and Wi-Fi will kill the battery faster (not to mention it's not readily available anywhere).
no I hate cloud storage as much as the next guy. It surprises me that they don't differ in power consumption, I assumed that as a given, yet after reading your response I Googled for it and you're right, so in that case I might as well just use a standard HDD. My current laptop HDD is dying though so I guess I have done more things you shouldn't do than you
Thanks for the response.