Just to put this in perspective based on your questions. I am 83 and trying to maintain or better a 585 Fargo by playing in 2 eight ball leagues a week using a parallel aiming system. One pocket is my favorite game but I do not get a chance to play it much. My custom cue is Alex Brick/John Davis with an OB Classic shaft. Using a home table I practice several times a week trying to improve specific shots. I don't gamble except for chump change. Many years ago I ran over a 100 straight pool and 7 racks of 9 ball. So basically I'm trying to get a little better before 'gravitation' takes its final toll.The REAL answer to that question is, 'it depends'. How seriously do you play and how much do you want to improve or at least maintain your game?
I mean the qualifying questions necessary to answer that question fully and comprehensibly is extensive.
Do you play with BHE, FHE, do you play by feel, do you use an aiming system. Do you play one pocket?
I mean the appropriate answer to that question depends on whether you're an apa 5 who just wants to play for league and an occasional fargo capped local tourney, bang em around with buddies twice a month, or whether you are a serious player and gambler looking to improve your game to the point that you're a threat in any match you play whether it be a regional tourney or a $500 a game one hole match.
Why are you looking to get a LD shaft would be one question. I ask this because there are normal deflection carbon fiber shafts that will play pretty close to your wood shaft if you're just looking for the advantages of CF...