[strat61caster]

I've had ZIISS for the past year+ on OE wheels in OE size (215/45/17) and I'm really happy with them, no experience on the RS3's.

ZIISS held up great on HPDE (4x 100-minute days, even double driver duty at T-hill 5-mile) and autox (~9x events average 5-6x runs per day) and DD (15k miles) and they still have tread but I believe the grip is gone. I'm like you OP, I'll keep running them as DD tires, because I'm cheap, until the tread is gone, I thought they would look like slicks by now but they do pass inspection with usable tread (although they're down to the bars). I'm not the fastest or hardest driver out there, especially during DD but they put up some 1:53-1:56 times around Laguna Seca my second and third days there.

I'm going to try RS3's on my OE wheels next as occasional track/DD tires (245 RE71R's for autox now on second set of wheels) just so I know both, get more experience on different rubber. I think Lots of guys like the Hankooks because they might have better grassroots and contingency support than Dunlop. But what do I know.

I really don't think you could go wrong with either, and when I was shopping the price difference was <$1 per tire in the same size, picked Dunlops on recommendation from local shop over RS3 and MPSS (in hindsight real happy I didn't pick MPSS), maybe someone local can say "Oh the XXX's handle our autox/track better because of the surface/temperatures/phase of the moon".

Edit: My research totally agrees, the fastest street tires right now are BFGRS and RE71R's but they're too soft for DD so you step down to ZIISS or RS3V2, if you're adventurous you could try something under 200TW but you may get the stink eye while autox-ing on AD08's or R1R's (which apparently come in a 200TW now so technically legal but no idea if they're good, some talk about them awhile back but if someone took notice they're keeping it secret)