I just got a 32 MB upgrade for my 200LX. I had been using an 8 MB palmtop with a 30 MB (uncompressed) flashcard. For me, the 32 MB upgrade has three big advantages: faster data access, longer battery life, and freeing up my PCMCIA slot.
The 32 MB upgrade adds a separate, 32 MB internal drive, in addition to the 2 MB of memory my palmtop came with. This 32 MB drive is MUCH faster than the flashcard I was using. I have added a data compression program called Jam to part of the new internal drive, and it is still faster than the uncompressed flashcard. Thus, I can keep more stuff on the compressed 32 MB internal drive then I could on the total of 40 MB I had before, and still access it faster.
The internal 32 MB drive consists of low power memory chips, so my battery life has been at least doubled over my old system. The chips do require power constantly to hold the data (unlike a flashcard), so if I let the batteries in my palmtop wear out completely, I would loose the entire 32 MB of data. I use NiMH batteries from Shier Systems and charge them in my palmtop, so I don't let them ever get very low before charging them. I also do frequent backups.
Finally, my PCMCIA slot is now free to use other types of cards. I keep acCIS and SSFaxer on the internal drive and have plenty of room to run them with my PCMCIA modem. I also have a PCMCIA ROM card with some games on it that I can keep in the slot most of the time now.
For me, the 32 MB internal upgrade is a better choice than either a combination Flash/Modem card or separate Flash and Modem cards.
(Both Jam, and SSFaxer are available in the HPHand libraries, I believe, and acCIS is already covered in the main article).