I'm currently writing a program for efficient use of expensive fabric and the user starts at the bottom left corner. As a person I'm more practical than theoritical so The Cartesian coordinate suits me fine.
I agre in the "ease" use of Basic is priotized over speed.
I'm surprised how well the present BBC BASIC hold the speed despite I use lot of arrays of structs and collision detectections. That little experience I have with PB also indicates a high speed as well.
Oops not 6205 but 6502...

I even remember many of the instruktions: LDA, BNE, ADC ect.
Back then you would use inline [assembler] in Basic and a call to get the speed.
I was and am still impressed how Micro Power managed to control the video chip 6845 with flicker free scrolling in mode 2, 160x256 pixels.
I have recently learned that the BBC Micro had 4 MHz ram speed and was one of the reasons why it's Basic was the fastest Basic.