I’ve been doing some winter tire research for my Infiniti G35 coupe.
From everyone I’ve talked to, going from high performance Michelin Pilot Sport tires to Michelin Pilot Sport A/S tires is not a good idea on the G35. I was essentially told that the car would slide around as if it were on ice skates (even at 4300 pounds curb weight!). Hmm, I’m not sure if I buy that, but being a RWD car (albeit with vehicle dynamics control), I do believe it up to an extent especially with the amount of power the engine is producing with various engine modifications.
OK, so Michelin Pilot Sport A/S tires are out of the question, especially if it does happen to snow up here. I also don’t want to waste money on tires, especially when they cost upwards of $400 to $450 per tire. Speaking of which, the stock rims on the Infiniti G35 Coupe (performance pkg.) run for $1000 a piece! I had one rim refinished a few months ago, at a cost of… get this: $313! I tried to repair the minor curb rash I spotted myself, but couldn’t find the correct paint color. The paint was what drove up the price of the refinishing job — $275 an OUNCE for the euro chrome paint used on the Infiniti G35 wheels. It’s a lead-based triple-layer paint that’s imported from Europe — shines three different colors, depending on the angle you look at the wheels from. Anyways, enough of that story.
My friend at a local car shop said the Michelin’s were out of the question (as mentioned), as were Pirelli’s and Toyo’s. I considered the Bridgestone Blizzak LM-22‘s and LM-25‘s, but they don’t make the required sizes I need for the front and back wheel configurations — resulting in differing tread patterns (bad). It appears that the Dunlop Winter Sport M3‘s are the only decent winter tires I can get for my car. Another option would be running the Blizzak LM-22’s front and back, since the LM-25’s don’t come in a 245 configuration. Either way, I’m looking at $445 for each front tire and $450 for each rear tire 
Quite pricey. I’ll do some more research and see if I can find a better set (and price) 
Update:
I trusted my instinct and went with the Michelin Pilot A/S tires to replace the rear tires! I don’t have any regrets about my decision. The new tires perform well and provide more dry/wet traction. Ride quality is still the same. All at $421 per tire