Mapcode is great, compact and precise.
Xaddress looks more like a traditional address so it might be easier to fit in , also gives you a hint of where the address is located, and is clear how to encode and decode.
But at the end of the day both are tools that might work depending on your needs.
>Designed to be used in low tech environments
What are supposed uses of encoded lattitude and longitude in "low tech environments", other than simple transfer?
1. https://en.wikipedia.org/wiki/MapCode