Sorry for any repetition of threads, but I'm new to the forum and looking for some assistance from all of you great bowlers.  Been bowling for years and just now getting back in to a regular cadence with practice.  Just bowled my 12th year at nationals a couple of weeks ago.  I haven't bought any equipment since the week before going to nationals and want to update/solidify my current arsenal.  As I said, most of my stuff is old, but is in good condition and still seems to react well.  Current...

Newest edition - Roto Grip Gem
Ebonite GB2
Motive Tribal Pearl
Hammer Onyx Vibe
Storm Natural Urethane Solid

I throw a 14# ball, with slower speed, (14-15) and lower revs.  I'm getting older, so can't crank it like I used to, multiple knee and shoulder surgeries.  I prefer to play up the lane if possible, but working on playing inside.  I seem to do better with symmetrical core, but that new Gem is a beast and did will for me at nationals in S/D.  I guess my ask, if anyone is willing to respond, is what am I missing?  Will mostly be bowling in mixed or men's leagues on a typical house shot, with the occasional tournament and USBC nationals each year.  Sorry for the novel, but any assistance would be much appreciated.  Thanks in advance!!