How bad is the tramlining of 275 tires on front compared to the stock 255's?

 

If by bad, you mean non-existent, then very.

Seriously, I didn't notice any at all going from the stock 235's to 255f/275r.

 

I've tried 255/40/19, 255/45/18, and 275/35/18 on my gt, street and road course. I prefer 255/40/19 for the road, and 275/35/18 for track. Surprisingly, I found the 255/40/19 on 9.5 wheels gave the best steering feel.

I also found almost no difference in tram lining between the 255 and 275. My Next set might be 255/40/19 & 275/35/19.