I wouldn't say FAR superior. Weight is about the same and everything else is a list of tradeoffs.

Shimano RS81 C24 pros/cons:
- Typical Shimano build quality (a.k.a great)
- More serviceable bearings
- Steel freehub body (eliminates gouging from cassette)
- Costs more
- Low spoke count/high spoke tension (if you break a spoke, the wheel will most likely be unrideable)
- Shimano spokes and nipples are typically proprietary and it may be hard to obtain replacements

Vuelta SLR pros/cons:
- Good value for the money
- Higher spoke count
- Spokes/nipples can most likely be replaced with off the shelf parts
- Cartridge bearings are harder to service/replace
- Aluminum freehub body prone to gouging from cassette
- Less brand "reputation"