In the US sites cause Canadian pricing is biased.
The s5 fully loaded came in at 56k, I picked the same options on the BMW and it came to 55.5K. Now if I add the factory 19's to match the factory 19's that come with the s5 then the BMW came in at 60k. Both cars had Red leather, upgraded paint and upgraded interior trim. So price wise you could go with either one.
I would like to see a head to head test, as the s5 has more power and longer wheel base, and overall a bigger car. The new 3 series is actually quite a small car imo, and might gain a more nimble advantage.
I seen an s5 in person a few days ago. The pictures do not do it justice. It sounded like sex as it is louder than I expected, and looked like a cross between the mercedes CLS and the 335 and a smige of the R8. Basically a shruken CLS best decribes it.
I will say I do like the interior and the exterior of the s5 much more than the 335's. But have twin turbo is nice too.
So the s5 might be better to woh your dates as it is quite a bit sexier than the 335....But I would have to drive one to see if it woh's my ass dyno.
Feel free to share your opinions.