what are some of best tonearms you own or experience with.

@sokogear
Rega arms - my main experience goes back RB300/RB600/RB1000.
When the first RB300's came out they were touted as a great giant killer.

Whilst they were excellent bang for the buck I could easily demonstrate that more expensive arm with a modest but great sounding cartridge could outperform a RB300/Koetsu combo for example. Moral of the story is that if you want to go up on cartridge, buy a great arm first.
The RB1000, well built, I have seen tracking issues with Shelters in our high humidity, Benz range tracked better.

When I sold my Platine Verdier I put an Audiomods arm on it at the request of the purchaser. With a modest Goldring MC I was quite surprised at the performance level - it easily despatched his SME20/V combo.

In my view the Audiomods is great bang for the price, but again stick to medium complinace cartridges for best results.

The VDH range tend to be medium complinace as are some of the Dynavectors along with Soundsmith MI's ( where you can select the compliance best suited ).

@atmasphere 

Nor me :) But it was obvious that the arm tube had resonance. If removing that 'killed the sound' clearly you have bigger fish to fry. 

Ralph, when I say killed the sound, in my experience the use of fluid damping on the SME V reduced speed and coherency. Similar with the analog survival damping. In my experience soft materials tend to store energy, but dont disspate it cleanly like for example carbon fibre or M2052. You tend to get backward reflections back into the cartridge at the junction of each change in material. The best damping if you must, is to use materials that have similar properties, but slightly different propagation speeds, example being the bimetallic damping Jonathan Carr uses in his top Lyra's.

There is also the option of mechanical damping - an example being the Naim Aro where the bearing design and mass distribution are used to provide damping - this is articulated in Martin Colloms review of the Aro.

When the SME V came out the thing that set it apart from most pivoted arms of the day was an organic midrange that appeared to be seamless, cut from one cloth, from mid bass to lower treble. Personally I still preferred the Sumiko MDC800.
Most criticism is that it is boring, I put this down to cartridge selection - as I said low compliance cartridges/Koetsu's not so good.

Another consideration is the turntable. As I'm sure you know from experience the way arms dissipate unwanted energy can vary considerably from turntable to turntable and in particular how it is terminated, armband material, coupling to plinth etc. This can explain a lot of variance in opinion, along with cartridge matching.

I would be interested to know when you dismantled the SME V and did some impulse testing on the armtube to determine the resonance issues - at what frequencies and magnitude were the resonant peaks.

 Adding the Analog Survival Kit increased the mass of the arm. For this reason it limited the cartridges that worked to ones that had lower compliance. 

This doesn't make sense, increasing the mass would help it work better with lower compliance cartridges - but for the aforementioned reasons I think its not the best option.

But what worked better was to use an arm that had an arm tube that was already damped and so did not need the Sumiko kit. The Tiplanar is an example of that; switching from the SME to the Triplanar was a revelation- better in every way. 

I agree with this in principle, but again it depends on how the damping is achieved. What I do like about the Triplanar is the functionality - the design allows very precise set up and alignment. In my experience when I was in the business, very few top end turntables were set up optimally, probably less than 10% and thats being generous. The ease and accuracy of set up in arm designs is underrated in my view.

The Kuzma 4Point is also a delight to set up, the precision and repeatability of the VTA mechanism is outstanding. VTA adjustment on the SME for example is awful as you would know, probably its archilles heel for me.

@dover - the next generation of Rega arms, especially the higher end ones (RB880, 2000- now 3000) have dramatic improvements. The 2000 came out with the RP10, which has since been replaced with the P10, so it has been a while since the new design and build was introduced. 

I can speak first hand as I had  a P5 with the stock arm, the RB700, which was very good, and at the advice of my friendly neighborhood Rega dealer who was adamant about the new arm improvements and guaranteed I would be blown away or he’d give me my money back for 3 months, I took him up on it and was absolutely blown away. As a matter of fact, I subsequently traded the P5 for the P8 and although it was a modest improvement, it was not nearly the discovery of the RB880. It has better cables and plinth and platter, and the plug in to the PSU is better, and the dust cover is much more convenient to remove while playing, so I don’t regret it, even though the price difference was more than the arm difference. 
I’d be interested to hear your thoughts on the RB880 or RB3000. I’ve been told it is not worth the difference for me to upgrade the 880 to the 3000 which I was considering. I think a $4K arm might be worth to consider for that level of expenditure, but for arms below that, Rega delivers more value for the buck.

I can't make comparisons to a lot of the pricey tonearms mentioned in this post but I think the Victor UA-7045 and UA-7082 tonearms have a lot to offer and they have been mentioned by at least two regular posters in this forum.
I have both of these arms and can't say enough about the build quality and engineering that went into them.
What really sets those arms apart from a lot of other arms is the ease of adjustments, both VTA and anti skate can be adjusted "on the fly" without worry of disturbing the arm when playing. They also have detachable headshells that are held rigidly in place by a locking clamp collar, uses any standard SME type headshell.
Go to the Vinyl Engine database and pull up the owners manual for a full description of the engineering behind this tonearm.

BillWojo

@sokogear besides the plastic material and the straightness issues of the VPI Tonearms which  I used to own, I was measuring excessive vibrations originating from the hanging dogleg plate as well as from the loosely VTA tower.