Yes, that's right. My W211 has the Goodyear F1 GSD3 tyres on them.
I got my 245/40/18 tyres at $350 each from Hock Tyre at 15 Kallang Way 3 (tel 6746 6686). At this price, it was at least $150 to $180 cheaper than the equivalent sized Michelin PS2s.
I think the GSD3 tyres provide quite good grip in both dry and wet and the noise level is also very acceptable. The V-thread is quite garang and helps to disperse water in the wet. Only thing is that it is uni-directional which means that you will only be able to rotate the GSD3 tyres back to front. I can't compare it against the PS2s, Rossos or SOCs as I have never used them before.
But at its price level, I think the GSD3s are very good value for money. No wonder they are often out of stock in Singapore.
I went for them mainly due to (i) its price, and (ii) its excellent rating for wet grip (which I rate as quite important as this is when we need the grip the most).
If you track your car often, then from the feedback I hear from high-performance car owners, go for PS2s and SO3s.
If you only drive fast & furious on the NS and other highways, then the GSD3s are more than sufficient, I think.