I use Paperless almost entirely for documents--bank and financial statements, tax records, etc. If I ever used it for receipts that was WAY back. From what you've seen, would DevonThink be better?
Since you are talking about financial documents, it could work. You can have multiple databases as well if you want them completely siloed too. If you liked the way Paperless worked, you should like Receipts as well. They are similar for the basics. According to my knowledge of Paperless 2 and my basic knowledge of the latest Receipts app:
• You have Contacts which is similar to Merchant in Paperless for receipts but can also be used differently because of its name. This will go well for it when Documents are added.
• I haven't found any Smart Collections like in Paperless but you have lots of other options. I never needed Smart Collections myself.
• Journal is the same as Collections in Paperless was.
• There currently is no types (receipts, documents, contact) in Receipts but I hear that is coming later (above post).
• Reports do not have the each receipt with info beside it kind of Report output like Paperless has but you have richer reports in the other areas that were lacking in Paperless 2 (don't know if Paperless 3 had them).
• No Burn to DVD/CD option, for hard backups.
• Haven't found any encryption options yet like in Paperless, if one wants that option.
• Overall, if you used every feature of Paperless, Receipts might leave you wanting more and DevonThink would be your only option, with a whole different way of looking at it and doing it. Completely different beast there. But if you don't need every feature in order to "survive," then it will do great as a replacement.
They also have a help file that you can read through for more info of the options available:
https://www.receipts-app.com/en/help
It is just a different app that is still at v1 and improving. Remember Paperless at v1? LOL Yeah, it took some years of major investment and time to get it to where it was when they quit on us. They also started with a different purpose in mind compared to Receipts.
The best thing is to actually try it out with the demo. No other way of really knowing if you are going to like it or not. If the demo doesn't do it for you, then try DevonThink, which will be more complicated but with more power, if that is what you want.
I personally think you should give Receipts a try first before tackling DevonThink, for the purposes you are stating. It is very similar to Paperless, just with some more modern features and yet less feature rich.
Did that help at all?