Rather a lot of people who had Commodore 64 computers also had the 1530 tape drive for a while, anyway:
I didn’t personally use a Datasette for more than a couple of weeks back then. I got my Commodore sometime during the summer of 1985, and got a disk drive for my birthday that August. In later years there were advances in tape-loading technology (speed loading techniques and the like), but in 1985 loading from and saving to cassettes was akin to digital masochism. While I have read that especially overseas there were Commodore users that primarily used the Datasette, in the US I didn’t know a single person who did.
I did, for about 48 hours, after which I dashed down to Toys R Us and snagged a 1541 disk drive. At the time, I had no idea how slow it was, but I knew it had to be faster than that horrible tape device.
Which was pretty damned slow:
[A] whopping 50 bytes/second. To put that in perspective, a 5 megabyte mp3 file (5,242,880 bytes) would have taken 104,857 seconds (just over 29 hours) to load. So while Commodore’s floppy disk drives seemed (and were) slow, they sure seemed fast to previous Datasette owners. Of course, 5 megabyte files were unheard of to home computer users in the 1980s. As a matter of fact, Commodore cassette tapes could only store around 100 kilobytes of data, which means to store that one single mp3 you would have needed 420 cassette tapes to do so.
Worse, if you had multiple (short) programs on a single tape, the little machine had to plow its way through programs 1 through N-1 before it could load program N for you.
Still, the 1530 had one distinct advantage: at $40, it was cheap. The 1541 disk drive was $200 in 1985.