The S-03 is indeed a great tire. They're hands-down the best performance tire out there when the rain starts falling. You can get a bit more dry traction with some other options, but nothing that offers more dry grip is comparable in the wet.

The one tire that comes close to matching the wet traction and is perhaps slightly better in the dry is the Kumho Ecsta MX (not the 712!!!) which is a good bit cheaper and also a very good option.

If you want something that's going to last a bit longer I would suggest the Yokohama AVS ES100. Good levels of grip although not up to the S-03 or MX, but they will definitely last a bit longer. They still outgrip things like the Kumho 712, Nitto 450, Toyo FZ4, etc.

So basically,

- S-03 if you want to spend some more money and get an awesome tire.
- Kumho MX if you want a tire that's very close to the S-03 but cheaper.
- Yoko AVS ES100 if you want some more tread life in exchange for a bit less grip.