I would get the G35 or G35x or G37 over the 328i or 328ci or 328xi any day if it came down to purchasing. If I were leasing, I would probably go with the 328 since BMWs lease cheap, cost nothing to maintain, get 30mpg on the highway, and are a pleasure to drive. Infiniti is seen as a very nice car, but it does not yell status symbol or I'm rich like the BMW badge will. For that reason alone, if I wanted a performance car, but not the hassel, I would get the infiniti. However, we cannot forget that for the lease rate of a former 325i, the 328i is not only an overall better car, but it performs like an E46 330i with just a little less torque, but an extra gear.
If money were in the equation the G35 wins for that young professional who wants a slick car aimed at taking on the 3 series. Also I heard the 335i and G35 with options, lease for roughly the same price give or take $10 and the right dealer... Car and driver said it, the 335i gives you e46 M3 performance in a much easier package. 0-60 in under 5 seconds as well as better gas mileage, 4 doors, an automatic transmission, a 10k discount, and 38 ft-lbs more torque. I'd take the 40 torque over the 35 hp for day to day running anytime. The 335i would have blown the Infiniti away and the value-hunters would have whined that if you compare the cars on paper option to option, and going by MSRP disregarding maintenance, that the 335i is 10k more. In reality if we compare apples to apples on option quality, and factor in the msrp discount it's more like $5,000. If you have the means, that is well worth it for a sleeper M3. The G35 does not perform better than an E46 M3, so the 335i wins hands down. The 328i is BMWs budget model, the G35 is Infiniti's super performance sedan, that alone makes the comparison uneven.