Both the Bajaj Pulsar RS200 and the Honda CBR 150R are popular choices in the sportbike segment, and they each have their own advantages. However, based on your requirements of decent performance and comfortable ergonomics for someone who is 6 feet tall, I would recommend the Bajaj Pulsar RS200.
The Pulsar RS200 is a larger and more powerful bike compared to the Honda CBR 150R, which means it will provide better performance. It is equipped with a 200cc engine, delivering a higher power output and torque. This should offer you a more thrilling riding experience, especially if you enjoy speed and acceleration.
In terms of ergonomics, the Pulsar RS200 is designed to offer a sporty riding position, but it still provides decent comfort for taller riders. Its seating position is slightly more upright compared to other fully-faired sportbikes, which can help reduce strain on your back and wrists during longer rides. However, it's always recommended to sit on the bike and take a test ride to ensure it feels comfortable for you personally.
On the other hand, the Honda CBR 150R is a smaller bike with a 150cc engine, which may feel slightly underpowered for someone of your height and expectations. It has a more aggressive riding position, which might not be as comfortable for extended rides.
Ultimately, I would suggest test riding both bikes if possible to see which one suits you better in terms of comfort, handling, and overall feel. Your personal preference and comfort level play a crucial role in making the final decision.