SME 309 or SME 3009r?

I wouldn't recommend rewiring either arm unless there is a problem.

The 309 already has silver litz, and the 3009R is worth more in its original condition.

As far as matching to your 16g Benz LP, the Benz is at the weight limit of both arms.

Max cartridge mass on the 309 is 17.5g

Max cartridge mass on the 3009R is 27g.

The effective mass on the 309 is 9.5g

The effective mass of the 3009R is 12.5g

Based on specs the 3009R should be a better match ( assuming it is in top condition ).

Sound wise the 309 will sound more precise, more grip due to the gimbal bearing design, the 3009R less precise but also less mechanical due to the knife edge bearings ( very free ).

Best choice will be very much dependent on your overall system balance and your preferences. They are swings and roundabouts in performance.

If you are looking to upgrade a real option would be to sell both arms and buy a better one.

For the great uneducated in this thread - as @neptune123 pointed out the SME 3009R is a totally different model to the SME 3009.

SME 3009 - light arm for medium to high compliance cartridges.

SME3009R - medium mass arm - stainless steel arm tube - released many years after the earlier 3009.

The SME 3009R is a much more sophisticated tonearm - for example the counterweight assembly can be adjusted laterally and well as forwards and backwards to ensure perfect weight distribution over the knife edge bearings.

From the comments above I would surmise that most of you have never heard a SME 3009R, which was sold predominantly in Japan.

As far as the Tinn Tiktok goes - they all had soft bearings - the SME 3009R will be still be running long after the Tiktoks have worn out.

@pesky_wabbit 

I trialled a MkIV on my Rock tt and was rather underwhelmed, although it did some things very well. The dealer told me that the IV was a bit of a dud and that I really should listen to a V. 

This is nonsense.

The later SME IV had the same bearings as the V - the main difference is the addition of damping troughs and minor bits to the V. If the IV is a dud in your dealers opinion then the V must be too - they are essentially the same arm.

I distributed SME for a brief period - I know these arms well.

@dekay 

The effective mass of my SME 3009II (non-improved/detachable head shell) is 12.5 grams.

Yes I was referring to the more common Series II improved - 6.5g effective mass and S2 improved - effective mass 9.5