I get this question at the DZ every year, and my answer is usually the same. I'm sure you can fly the new canopy and land it safely 99% of the time. The time I worry about is that 1% that shit hits the fan and you aren't experienced enough to handle it. Are you ready for that responsibility for injuring yourself severely or even worse someone else?
Take your time and learn the 150. It hurts alot less to screw up on a lighter WL than it does on higher WL. (Commen sense) If you plan on being in the sport for a good amount of time, you just need to slow down. The sad part is all instructors aren't good ones and can give you some terrible advice.
I'll give you an example of a recent jumper. He was flying a sabre 210 and wanted to start flying something more aggressive. He showed up at the DZ and was flying a crossfire 2 169. After I found out I had a long talk with him about his choice and the reasons he went there. He still decided to keep jumping it. Got professional coaching at other dropzones and was doing pretty well with it. Fast forward about 100 jumps and that 1% came back and bite him in the ass. I'm still not sure how he didn't break himself but he walked away with a bruised ego and ended up taking a few weeks off to reconsider his canopy choice.
Most people that make posts like this already made up their mind and it doesn't really matter what people think. They believe they are better than all the hot shots that enter the sport. Some make it, but most don't.
good luck and best safe.