For exterior styling, its a tossup. I think the Venza looks better overall whereas the Lexus looks kind of like a child going through through that middle school awkward phase. Certain areas are larger and more exaggerated that before yet the rest of the car has not quite grown enough for the more mature feature. The Venza on the other hand is more resolved, if it were not for the grill. I don't see why midsize crossover designers feel the need to channel Gehry when styling the grills. Look at the Murano, Edge, and now the Venza, its too much.
When in comes to interior design however, the Venza wins hands down. Toyota needs to be careful not to overclass Toyota models as they transition into separating Lexus and Toyota ranges worldwide. Previously Lexus models were badged as Toyotas, with the RX being the Harrier in Japan. Now that Lexus's are sold in Japan, they have the opportunity for more overlap. The Venza serves as a good example of the problem. Its interior is much more resolved compared the over-stylized cockpit of the RX350. I haven't tried out the new remote touch, but I think I touch screen will work better. The curved nature of the RX dash presents the occupants with a large expanse of plastic whereas the Toyota seems to have a much more balanced appearance.
If it weren't for the Lexus badge, I wouldn't ever consider purchasing the RX350, and I think thats exactly the point. Its kind of like these T-shirts I buy every summer. I wake up early to stand in line for a 20 dollar t-shirt that gets progressively uglier every year. I often feel like they try to make the shirt ugly just to laugh as people like up to buy dozens. Toyota is doing exactly the same with the RX350. The Venza is the same car without the premium badge, yet people would continue to pay for the swoopy "L" if they can.