Ready to feed vs powder formula

My daughter is FF. She is 3 weeks old. I have been giving her similac alimentum powder - she is so so gassy and it makes for a miserable experience. I recently gave her the ready to feed kind and omg what a huge difference. It seems to be thicker than the water & powder and she does a lot better with it. Has anyone else experienced this? Just wondering is there really a difference? I did also buy her preemie bottle nipples because she kept choking and drinking so fast that I think that also made her gassy. She is only around 5 pounds too.?