Upgrade from TW Acustic Raven AC-3 to what?

If you have the money to spend, I see no issue in going to Black Night or the da Vinci to match your tonearm / cart combo and both should do more of what you are looking for.
Dgad might want to add some comments here as he has gone from AC-3 to BN and he states it is very much more open and not dark at all.

I somewhat agree that the AC-3 can be a little dark sounding and a touch warm in the upper bass - however I luv that trait about the AC-3 as it is a long way from stark and lean.

Lewm is correct, a very nice vintage DD or a GP Monaco should have a tighter bass.
I just bought an Exclusive P3 DD table and the biggest difference between that and the AC-3 is the way it drives and controls the bass. There is no upper bass bloom or overhang and it controls the bass and subsequent mid and upper bass with precision. This gives you a more clarity in the upper bass and lower mid range.

As with anything, there is no free lunch and with some recordings this is perfect, with others the AC-3 is clearly preferable.

Going the vintage DD route will cost less than your cartridge and you will get a 2nd turntbale which is always good. You can then play whatever table suits the style of music you are playing, as there is never a best of anything.

you have many choices available, so have fun

The Raven doesn't have to sound as dark as it looks (hello Syntax ;-). If you want to keep that table, I recommend to place it on a effective isolation platform first. A Vibraplane should work (need some extra weight on top, i.e a 20 kg slate slab). You would be amazed how much more space and transparency, and in consequence enlightenment in terms of sound this machine could provide.

Next steps could be: reduce three motors to two motors, placed opposite to each other. Use one long driving media such as magnetic tape. Two opposite positioned motors help to free table's bearing from being loaded one-sided. You can hear the effect very well on recordings of solo voices. They appear more accurate shaped, more free.

Don't put the motors on the same platform as the turntable itself.

Some more fine tuning is possible with isolating platter mats.

If you want to go further, change the DaVinci to a FR-64s, and your system to a ZYX UNIverse or Lyra Titan i or a FR-7f - and darkness and narrowness should be gone (if your phono is not another bottleneck)

I own a Raven AC 2 since about three years now and have done all treatments mentioned above.

Two different audio fellows, listening guests at my place, said that my Raven sounds notable different to all the Raven set ups they have listened to before. Not only different - it sounds better: with space, effortless - not Raven like. I'm still happy with it, too. Syntax would only believe it when hearing it at my place.

So, before you spent money in a hurry, try out some things with the Raven. It is not really just a plug and play table but rather need some care.

Nevertheless, honestly, there are better designs. Just money gives no access to these.

I have heard this table a few times and its not dark sounding at all.
First off, the cart- what cart are you using it with ? try some clearaudio carts if you want it to be more detailed and neutral. Lyras are also on the neutral side of things.
2nd- as other suggested, the isolation stands. Critical mass stands (CMS) is a good place to start. Makes the most out of this TT.
3rd- arm- I heard this table with a variety of arms and each has a different sonic signature. Graham Phantom II, Triplanar are the arms of choice.
4th- as what people have shared in this thread, the vta and the vtf all makes a discernable difference with this TT.
5th- the phono cables again, can impart sonic signatures. Try some nordost phono cables for a lighter, airer presentation.

Good luck. Its a good problem you have!
If all fails, the SME 20 would be nice as well as the TW Black Knight. CLearaudio is also another candidate.

Walker, period.

I believe every well healed audiophile should own this table once in their life. It is the most revealing table you will every hear. There is n-o mid bass bump, and there is that enormous soundstage that you will remember forever. I had six years on mine and I still think about it most every time I play a record.

Peter

Peter, "Well-healed" indeed. Maybe after dropping that lead platter on your big toe. I have been impressed by the Walker too, every time I have heard one.