I wish I would have been a little more hardcore at the time like you, I probably would have got the oled vita instead of the vita slim. I just added the New DSi XL to my wishlist next to my oled vita. So thanks for the info, legit didn't realize ds games look better on the DSi.
As for jumping in to collect for the 3ds, better late than never.
I was about to pull the trigger on a New3DSXL and in my typical hyper analytical fashion checked the differences between EVERY MODEL because they released such a variety of different units, it started to get murky after the Lite. One thing I wanted to ascertain was the last model to play GBA games (lite).
So the GOAT collection would be the GBA SP late version with better screen OR original GBA with upgraded screen (it has better ergonomics, shoulder buttons), a New DSi XL and a New 3DS XL for access to N's entire portable library with the best hardware for every game with no compromise.
I do kinda wish we could have had one end-all portable, or at least a single unit for the whole DS family lol.