I would take any BMW, any day.
1. Any BMW is nicer than any Lexus, IMO. Don't get mad.
2. I don't like the styling of the IS300(the lights, especially).
3. BMW has a reputation. BMW is an accomplished car company with many achievements under its belt. Winner of Le Mans, maker of the McLaren's engine, the whole line of M cars. On the other hand, someone says Lexus, you think of a big 4 door sedan for old rich people. Lexus has no reputation. What is the best car Lexus has come out with? The IS300?? Pretty crappy. SC430?? The man who designed that needs to disposed of. Nothing special about that car anyways.
4. The IS300 has no manual transmission!!! What's up with that Lexus??
5. BMW's are built better.