They are great mics, no doubt about it. But, they are also a very different mic than the SM57.
The SM57 is dynamic and the Royer being a figure 8 ribbon. What kind of results do you want? Do you record full time, or do you just want to make better clips?
If you just want a mic for better clips, home recording there are a ton of cheaper alternatives. First off, I'll say keep experimenting with
the SM57(s). Many people get great results out of them. If you want a more full bodied sound, mix in a ribbon mic. But, you can buy one much cheaper than the Royer.
Check out
the CAD Trion 7000. Flayangus makes his Elmwood clips with it, and they sound fantastic. I also think it's below $300.
Also, I've heard the SE Electronics ribbons are great as well. If you want to be ultra cheap, check out the Tbone ribbon mics.
IMO, there's no reason for you to spend that kind of dough on a Royer, unless you fully intend on making pro recordings full time. But hey, if you have the dough to spend, be my guest. I'm just saying, there are MUCH more wallet friendly options out there.
My $.02
-Joe