The main issue with using retro devices is software. It can be incredibly difficult to locate it! It seems that obscure ancient OS's are better preserved than for example Palm OS or Sharp Zaurus software.
This sounds like hogwash, but BSD 386 is around, so is CP/M. Need some OS/2 Warp apps? Yeah you can get them.
Maybe I am exagerating a bit. I mean, you'll probably have to work for all the above. I really wish people had used sites that are still around for hosting. As shit as sourceforge became, at least it is still around and preserves a lot of stuff that would have otherwise disapeared.
This brings up another related topic: shareware sucks. No redeeming quality. The main influencer on this opinion of mine is that when a company releases shareware, then that company fails, the software is dead. Dead. Dead. Hopefully some enterprising hacker patched the software to defeat the protection, but this can tend to make an app buggy. Software released under an opensource license can still be sold. It tends to be better preserved as well.
Think about that the next time you write software for the latest and greatest platform. It will assuredly be crusty, dusty, and forgotten years from now. Do not do a disservice to the future. Set it free.
"But the work I did, the sweat of my brow..." -- will all be for naught the day you die. Don't be a jerk. I am not talking out of my ass here. I have written software -- gave it away. I have released over 90 albums of musicon my own label (and a dozen labels owned by others on 3 continents, digital, tape, and CD) and have given it all away for free. I created the cover art for hundreds of albums for French label Wulfrune Worxx (which is featured on numerous YouTube videos and pop up on tape trading sites a lot), did all that work for free. Some things, IMHO, should be done for the love of it. Hamstringing the future is a dick move.
Note: today I figured out a memo beamed from a palm device to the Zaurus comes across as a textfile. This entry was typed on a Handspring Visor Deluxe using a Stowaway keyboard, beamed to a Sharp Zaurus SL-C3000, renamed and ftp'd over 802.11b to a Raspberry Pi 3 which then scp'd it to another then was posted to RPoD via git. Rube Goldberg eat your heart out.