I have several plain jane cues from numerous makers and you can do a search and see my collection anytime on this forum. THEY ARE ALL NOT MADE THE SAME!
I would focus more on construction methods, pin type, ferrulle type, ferrulle size, Tip Type, shaft taper, cue length , & etc.
Based on what I have read on this forum for a plain jane i would suggest the following,
material: maple plain jane is best or cored with maple cues no points!
examples: tad's, sw satin's & etc
flat faced wood to wood:
examples: tad's, sw satin's & etc
3/8 16 pin or Radial Pin:
examples: tad's, sw satin's & etc
lbm (linen based Melanine) 3/4 inch ferrule:
examples: tad's, sw satin's & etc
kamui or moori tip:
example: look at pro tip list and these 2 brands dominate mostly soft & medium
Shaft taper: depends on your stroke length
joint material: aegis sleeved joint
examples: tad's, sw satin's & etc
ALL THESE GREAT PLAIN JANES HAVE ONE THING IN COMMON AND THAT IS MAPLE WOOD FROM TIP TO BUTT AND NOTHING IN BETWEEN. NO METAL, NO POINTS, NOTHING TO DISRUPT THE VIBRATION FROM TIP TO BUTT!!!!!!!! PLUS, THE USE OF THE SAME SPECIES WOOD FROM TIP TO BUTT! THIS MEANS THE ACOUSTIC VIBRATION PROPERTIES OF THE WOOD ARE UNIFORM AND NOT DISRUPTIVE! PLUS, THE BALANCE IS UNIFORM BECAUSE THE WEIGHT OF MAPLE IS UNIFORMLY APPLIED. THE RESULT BEING NOT BACK HEAVY AND NOT FRONT HEAVY BUT JUST RIGHT!!!!!!!!!!!!!!!!!!!