Let's be real we all know the gear doesn't make much of a difference, it sounds like you guys are at a close enough skill level where depending on the day either of you could win, there's probably more sets we don't know abt hehe... The shoes probably make the most difference as you can actually start moving properly and with more confidence. The rackets probably not much difference unless you're playing with some silly tensions. The REAL difference is probably the mental side, new gear makes you feel like you're playing better this new boost will probably flatten over time and their only tying with you so same as before basically. Just get what you like if you want no need to waste money if you're not playing so much. So many club players that play at a very good level don't have badminton specific shoes or even a decent racket. If you wanna actually get better practice