@Wintermute_BBS I can try 😅. So Tapecart (TC) and Tapuino (Ta) come to mind. The TC (with and without SD) is tiny and cheap. Originally developed with only 2MB of internal flash storage, it was meant as a way to load stuff very quickly into the C64. I think the max. transfer rate you can achieve per second is beyond what a disk could do. But it does not support TAP images, so only onefilers and the special tcart format, that is a bit like EF. It was from a time when Easyflash cost around 60 Euro, and this one you could buy for 15/20 or build yourself even cheaper. There are some tcart versions of games on csdb, but it never gained nearly as much attention as EF. I still use the TC SD when going to parties, want to pack in original hardware and just a very small device with some games.

The Ta on the other hand basically is a fully virtualized Datassette. You can experience the joy of slow loading times to the fullest with this thingy 😄. I have one with a display and I actually use it only for tranfering TAP images to real tapes. You can do that with several devices, there is also an adapter for the 1541Ultimate, but I simply don't like it that much. The Ta seems very reliable in that regard. And you can also dump tapes onto it (again, other devices can do that as well). Theoretically, you'd have all the TAP games ever made at your fingetips here, but since you need to browse through them with that little display, clicking through one by one, you'd go mad 😄.

Both solutions, the Ta even more than the TC, are for people who were and still are fans of tapes. If you never really liked them, there is hardly a use case for them. SD2IEC does stuff very differently compared to TC, but both can't load TAPs. Ta basically only loads TAPs but you can't do much else with it. I'd say it's mostly for preservationists and tape aficionados.

Just my 2 Cents. Hope it was of any help, although I can't offer any "see, that's why you need one" moment 😅