Tonearm for TW Acustic and heavier cartridge

I may be looking to get TW Acustic Raven AC in the next 6 months. Right now I am auditioning a Raven One with Raven 10.5 arm in my system with Koetsu Onyx cartridge.
The sound is wonderful on piano, vocal, small jazz band but I find it a bit too mellow, perhaps a bit too sedated on rock/pop and large scale orchestral work. I was going to burrow Raven AC to try after this but friend of a friend snatched it before I could listen it in my home. Anyway, I will have to wait awhile before our local dealer will have a new one in that I can listen to.

Anyhow, I am wondering about arm that I can use. Raven 10.5 arm seems nice enough but there a few quirks that I don't like. VTA on the fly is certainly not as easy to use as some other arms. I am plannng to use either Koetsu Onyx or Air Tight PC-1 supreme with the new table. A friend suggests that I should look at SME V rather than Phantom (which seems to be a popular arm with TW Acustic) for heavier cartridge. Durand Talea looks interesting but a bit too cost prohibitive at this time but might be an interesting choice when I want to add second arm.
Arms that are a bit easier to get here are Graham, SME, TW Raven or I could also get older Micro Seiki arm from a friend. So if I want to mount either 12 or 12.5g cartridge, what would be a good arm for these combinations.
I have two friends who use the Phantom with this table; one uses an high end Air Tight and the other one of the better Dynavectors. Both are happy with the results.
I think Jeff Catalano was running a Jade for while, and may still. He may be able to recommend an arm for the Onyx, which I believe is around 13 grams. The Jade, which I use on a Vector,is approx 14 grams. This is according to specs on Acoustic Sounds catalog, if my memory serves. In addition to the Graham, I have also heard that SME arms work well w/ stone bodies. Beyond that, it seems to get a bit esoteric. I have heard the Saec arms work well because they have higher mass.Honestly, have also posted this question, but it was basically just which tonearm works w/ Koetsu. I didn't get much of a response, so perhaps there aren't many. I think the Analog room in San Jose, has Graham,SME, and Koetsu. The Saec was a bit off the charts for me to seriously consider. I would look in to the Reed arms, if I were in the market.
Thanks for the comment so far.
Unfortunately, I am not in the position to make any fair comparison so far. The comment is not specific to Koetsu only but more for cartridges around 12-13g in general (if I am not mistaken , Air Tight is 12g, Koetsu Onyx is 12.5g although with much lower compliance) but looks like Graham or SME should be ok. Any specific comment on difference in sounds? Gathering from various comments around here, people tends to be a bit more negative on SME and Phantom seems to do no wrong. Raven tonearms have many followers but also quite a few distractors. Unfortunately this is going to one of those things that will be difficult to have a proper audition before buying.

Thanks for the comment on Reed and Saec as well and I will look into those.

VTA on the fly on the Raven 10.5 is far easier than on the SME V (which does not have VTA on the fly). And as for comparing to many other arms, is by far the best VTA on the fly system I have ever used.

As for the Koetsu Onyx. It is a bit of a "mellow" cartridge. That is why you buy it. As for the Air Tight or other cartridges, what you determine by matching the Koetsu will not apply 100% or even 75% to an Air Tight as the compliance is different between the cartridges and this is of more importance. Also the PC-1 is not a mellow cartridge. I think you might just like it.

The Raven arm is one of the less mellow arms I have used (if that truly means anything). But I do have, and have had some mellower arms that have matched well with my more lively cartridges.

You also, need to consider matching is everything. Even in an ideal match (perfect arm for a Koetsu) the majority of the stone bodies will be mellow. The only one reputed to be lively is the Coral Stone but the cost is up there. Try an Allaerts MC2 Finish on the 10.5 and you will get the best of all worlds with a wonderful combination.
Dgad, thanks for your comment.
Currently, I am using VPI Classic with all the upgrades (SDS, ring clamp, valhalla wire/VTA tower etc). (I know some people will say that Air Tight and Koetsu that I own is way beyond what the Classic can do but let's leave that for another day).
I find Koetsu Rosewood way way too mellow for me on VPI but Onyx seems to strike the right balance. When switched Koetsu to Raven One, things got too mellow again. I have not yet try Air Tight on Raven One but will do so in the next few days.

VTA on the fly on Raven is not bad but I miss the dial on VPI (Graham, Vector also). I find the scale much easier to make things reproducible when I want to do fine adjustment back and forth for comparison. Since installing Soundsmith Counter Intuitive on my VPI, azimuth adjustment is also a breeze and more importantly easily reproducible and VTF is almost as easy as screw in counter weight like Raven. Of course I am not trying to claim that VPI 10.5 is in the same league as Raven tonearm sonic wise (well, there is no way for me to try both arms in the same turntable anyway) but from ergonomic standpoint, VPI seems a bit more user-friendly.

Anyhow, for now, I plan to keep VPI and add a second table which I could find locally and TW Acustic has a lot of things that I like. Currently I have Koetsu Onyx, Air Tight PC-1 Supreme and Dyna XV-1s (don't know why I kept buying more cartridges) but hope to get an ideal turntable set up that I can use all of these cartridges effectively.
Put some nail polish as a marker on the VTA dial. That is what I did. Looks great and does the trick for easy repeats.
TW 10.5 arm works wonderful with my Transfiguratin Orpheus very dynamic wonderful micro/macro dynamics large deep soundstage great depth wonderful highs midrange.The bass is very fast and deep with great dynamics.If you set this arm up right it is truly world class.
Oh yes there are 3 conterweights which should match even the heavyest cartridge.The arm has a compliance of 14grams which is ideal for any cartridge.
Thanks for all the comment. I just switched Koetsu out for Air Tight PC-1 supreme that I have been using on my VPI. Looks like it is a much better match than Koetsu. On VPI, I think Koetsu and Air Tight was pretty close to each other in term of level of performance however different their characteristic is and it was a tough choice which cartridge I would use. However, with Raven One/Raven 10.5 arm, Air Tight really outshines Koetsu quite a bit.