2015 IS350 vs. 2015 Q50S, in terms of best value on the used market?

I've been looking at these two sport sedans as my next car and at this point, I feel that the price difference is enough to question the value.The Q50 definitely has its faults with the steer by wire and reputation for infotainment issues, but the former looks to be an optional add-on and the latter seems to have been mostly fixed for the 2015 Model Year. As far as the engine goes, it looks like the 2015 kept the 3.7 VQ engine from the G37 (which I actually really like). The lowest price in my area seems to be hovering around 24k (40kish miles).As for the IS350, it comes with the super-reliable 3.5L engine from the last generation IS and a much nicer interior. I haven't seen many complaints at all about this model. However, the price hovers around 30k+ in my area for these.I guess what I'm trying to ask is; do the differences between these competitors really warrant the 6k price difference on the used market? Any current owners of want to drop their 2 cents on how they feel about the value of what they paid? via /r/cars http://ift.tt/2t8mXaW