Do you have an opportunity to take the 12/14/18 for a test drive? Perhaps do a side-by-side comparison?

I have a 12/14/20 Ludwig Downbeat and a 12/14/18 Ludwig Jazzette, and the difference is huge between the bass drums. The 20"x14" can do it all, and the 18"x12" is a little more pigeon-holed. They each have their own vibes. If I had to choose one to play for the rest of my life, it would be the 20x14, but that doesn't mean the 18" is shabby at all. It comes down to personal taste. I know most guys would chomp at the bit for a 12/14/18 Gretsch round badge kit, but it comes down to your decision. If I were you, and this were possible, I would jump on the bop kit deal, and try both out for a while--tinker with heads and tunings, and eventually one will stand out as being sweeter. Good luck, and let us know what you end up doing!

I always had 22s and always wanted a 20. Then I had an 18 on a gretsch catalina club and it was a bummer cuz it came with a riser on the pedal and when I took the velcro off the goddamn thing wouldnt stop moving, now that I got a 20 with my rogers it cant be beat! literally it can and does tho ha

Does the 20 fit in your car? If so, save yourself some dough and stick with the 20, especially since you already know how to play it well.

Think of all the 20 players in the Jazz idiom, many of whom used 22 or 24 if there was room for it, they could fit it in the transport and the band was full-size. I personally prefer 20,12,14 because it is considerably lighter to carry, but in a larger room, I used to move up to 22,13,16 in a heartbeat. 20 works for almost anything though, if you want to have a versatile drum.

As kookadams said, the jack-up thing can be a pain, though most guys didn't use jacks when 18's became popular (and you could have used a swivomatic pedal that can adjust to any size bass drum - little swivo plug in here).

Then if you get the 18 and need a bit more umph, you could be out of luck. I had a set of Rogers with an 18 and I let it go because the 20 was so much more practical for all-around play. Of course, where I am living (KSA), I can't play anyway, so doesn't make too much difference right now.

The 18 is perfect for small group acoustic jazz where you want the drums pitched fairly high and singing. If you are used to the thud or thump of your 20, you won't be happy with the 18. If you've been tuning your 20 up high and letting it ring after the stroke then you'll love the 18. I have been using an 18 forever and have never used one of those riser things. The beater strikes about an inch higher than dead center but doesn't affect the tone. Are the 2 kits from the same era and do you need to get rid of your kit? IMHP, if you can keep your 20/12/14, the 18/12/14 would be a wise investment anyway, playing preferences aside.

Love it when i get my bass tuned right and it sings like a note. I had a black diamond pearl 12 14 20 kit where the bass drum had characteristics of an 18.. shouldn't have sold it.

There is no way i could keep both kits unless i win the lottery

Go for the 18/12/14 and keep your snare. Is it the Max Roach model?

I prefer the 20". I can't seem to get a good sound out of my 18". Might just be my tuning abilities though. I agree that you should try to set up a side by side test.

The only 18" Bass drum that has that special sound we were looking for & which happens to be the best drum i own is my Gretsch 16 x 18 floor tom conversion.

My 20x14 Ludwig club date bass drum can sing the phone book. My vote is for the 20".

I have an 18" bass but it's like the little sister always trying hard to impress, being overshadowed by her older sibling the 20". Kind of like Jan Brady and Marcia Marcia Marcia...