Upgrade to SSD. Then invest in a decent backup system. You'll need it.

SSDs are fantastically faster than spinning glass and rust dust platters (orders of magnitude faster) BUT SSDs have a surprisingly low MTBF.

Based on anecdotal comments from SSD early adopters, you should not expect your SSD to last as long as the HDD it replaces. While you can often assume you will get 5+ years of service out of a good HDD, you should probably plan on replacing an SSD after about 1 year of heavy use. It certainly may last longer than that, but better to be prepared than surprised.

This is not an indictment of SSDs, but just a reflection of the relative maturity of the respective technologies - the HDD industry has 30+ years of manufacturing and reliability experience, whereas the SSD industry is still relatively young. SSD reliability and longevity will continue to improve, but it has a long way to go to catch up to HDDs' lead.

So after you install your blazingly fast SSD, invest in a whole-disk backup system and back up regularly to a different drive or NAS. And immediately after creating your first backup, do a dry run of the restore process to make sure it actually works.

SSDs are more expensive per MB and have shorter life expectancies than HDDs, but the dramatic SSD performance boost over HDD more than makes up for these drawbacks.

You know you should be making backups anyway, but the longevity and reliability of HDDs has made us all complacent. Time to fix that.