I'd agree that there's potential – look at Essential Grid please. Their failing for me was that the sort options once an output has been achieved is that you can only sort by date/author etc. Wasting all that beautifully crafted cats/tags…
Appreciate your freebie – I'll take a look once my site is back from having been fatally broken by another developers plugin update 🙁
All the best.
PS: since I'm here – would you be interested in looking at simplifying/modifying your principle for my site? It might do us both some good… I could contribute to the dev time.