You're comparing two totally different tires. RT-615s are overkill for a daily driver. They have a 200 treadwear rating and are really only meant for dry conditions, especially when you've put some mileage on them. Neo-Gens on the other hand offer less grip but are cheaper, last longer, and will give you better all-weather traction so long as you stay away from densely packed snow. I'd go for Neo-Gens in 215/45.