I think for most beginning players and many advanced players even, playing with your own cue will go a long way toward shooting more consistently.
I know a guy who always plays with a house cue and is quite a good shooter. Well he got talked into joining a league, which required him to play at other bars than his regular hangout. One of these bars had really bad house cues. So this guy borrows the house cue he normally plays with to take to the other bar. And he played just as good as he always does.
So what he is doing is always playing with the *same* cue. It is a house cue, but he always plays with the same house cue. (One day the bar he plays in decided to get new tips for all their cues including this guys favorite cue. Well his game went downhill with a quickness!)
Then I've read about pro players who have had something nasty happen to their favorite cue. (Shaft break or whatever.) Then not play as well with their new cue.
I've seen a lot local players switch cues, then have their game go down the drain. Or even just get a new tip and have their game go down the drain.
So I think it is *most* important to always play with; the same cue, same type of tip, same hardness of tip, and same radius of tip (nickel, dime, etc.).
Second most important, if you are going to get your own cue to play with, might as well experiment with different shafts/tips and use what works best for you. Then stick with that same specification of cue forever.
If you have been playing for 20 years with a certain type of cue, then switching to something totally new and different probably will hurt your game.
I've only been playing seriously for 2 years. So I am going with all the latest in new technology. I switched to a Meucci butt and a Predator 314 shaft in January and also changed the weight of my cue. (Finally figured out what I wanted.) I was getting into the money in tournaments before switching, then have not done this much for the past 4 months. I've been in the money the last 3 nights at tournaments and won 1st last night in a small local tournament. So I'm just now (after 4 months) starting to feel comfortable with my new cue. It was hard at first to adjust to the weight change. And the hardest thing to adjust to has been aiming with english on long shots and my new low deflection shaft.
Also to be fair, I've also been learning/practicing a *ton* of new shots, so this has also thrown my game off the last couple of months.
Once before, I switched shaft size and my tip/tip radius, and that took me two months to adjust to. I went from a 13mm nickel shaped medium leather tip to a 12.5mm dime shaped pig skin hard tip.