Compared to a Day-Timer, leather bound address book and calendar, even the Newton was compact. If you were the type that was never without one, a PDA was a godsend.
I was not such a person. I was, however, a gadget person and every PDA that I owned during this era had expansion slots.
The Handspring Visor was my first. It took the PalmOS and through springboards could be a phone, a GPS device, connect to online services, play MP3s, tune in radio, carry a library worth of information, connect to Bluetooth devices, be a credit card processing point-of-sale device, it could even be a digital camera. The potential was essentially limitless and when combined with a collapsible keyboard you could even do fairly complex word processing, spreadsheets, databases etc... As for games, Not only were there some fairly advanced, for the time, games available, it was more than powerful enough to fully emulate the, then current, GameBoy. Putting it on par with the most popular handheld gaming system of the time.
When I went to Windows CE/ PocketPC / Windows Mobile I went with the Dell Axim which had SD and Compact Flash slots which allowed for all the above plus massive (for the time) storage potential. Some models even had WiFi integrated.
One of my coworkers had seen my PDAs and came to me for advice and we set her up with an iPaq with a phone module that made it the first device I would classify as a fully functional Smart Phone I even experienced that delivered most of the capabilities of a modern smartphone. WiFi, Bluetooth, Camera, Web Browsing, Internet Connection Sharing/Tethering, MS Office, MP3s, etc... Unlike the Handspring which could do one or two of these things at a time, the iPaq could do them all simultaneously, which is why I consider it a smart phone when the Handspring never qualified in my opinion.
So yes, a lot of PDAs back then were little more than an electronic version of a paper organizer, but if you had the know-how, deep enough pockets and picked the right device you got to live in the Smart Phone future years before virtually anyone else thanks to PDAs.