I guess this really depends on what you're looking for in the Rayquaza, but if you're looking for IVs, the Rayquaza isn't worth very much at all and isn't an overly impressive find. As of Generation 6, all legendary Pokemon encountered will have three stats automatically set to have perfect 31 IVs, presumably as a measure to make soft resetting legendary Pokemon less of a grind. So the Rayquaza's IVs aren't as impressive as they seem; its low Special Attack and Special Defence IVs may limit its potential in competitions and confine its moveset options (though its nature already does quite a lot in that regard).
Its decent Jolly nature and decent Speed IV are really all it has going for it competition-wise, and the nature can easily be replicated using a Pokemon with the ability Synchronise. Speed is perhaps one of the worst stats to lack IVs in as it allows Pokemon that share the same base stats to creep Rayquaza's Speed and move first, so the IV is subpar even though it might not seem that way on paper. Sorry to disappoint, but the Rayquaza you got isn't a very impressive find, and is probably the type of thing you'll come across most often in your IV-resetting endeavours. I'd definitely keep resetting in this case.
The 237 Attack it has is very interesting, though; it suggests that the Rayquaza has somehow gained 4-7 Attack EVs. Did it knock out any of your Pokemon whilst you were fighting it? Was it included in any other battles or receiving EVs from the Exp. Share? If so, this may be where it gained those EVs for the extra stat point. It's also possible that the calculator you used had an error or that Rayquaza's stat distribution was completely different; the only way for a level 70 Pokemon of that species to have 237 Attack is for it to have a positive nature in Attack and 2 IVs in that stat. Unfortunately I can't come to a conclusion on how this happened.
Calculator used to play with Rayquaza's IVs and stats
Useful article for soft-resetting legendary Pokemon
