SL1200 upgrade tonearm or replace cartridge?

If you check out Jeff Dorgay's article in ToneAudio's Issue 22, he replaces the internal power supply with an aftermarket one, and the mounts an SME 309 and reports the results. An excerpt:

...if you want to push the boundaries of what you can achieve for an investment of $2,000 in a turntable. I’ve had the opportunity to listen to a lot of turntables in the $2,000 - $3,000 range from Rega, VPI, Pro-Ject, Music Hall, etc., and for my money, this one is the one to beat.....

Don't know if this is much help to you as I have no experience of the cartridge other than I just found out how much it costs. It seems over priced (match wise) to the cost of the turntable (when these could be purchased new that it), but given that you were thinking of upgrading the tonearm, have you thought about the SME M2 ? these look more suited to your turntable, and I expect would be easier to fit, though whichever one you choose will need a custom plate making for it.
With the stock tonearm (which I happen to think is pretty good already (with the right cartridge), why not try a downgrade to a higher priced MM cartridge ? There are several makes out there that might suit that arm better than the Benz and give a better sound, and give a better sound because of this.
Ortofon, Goldring and Audio Technica make good, higher end MM cartridges, my favourite being the Audio Technica AT440mla, though your Benz being such a high end model, you might not be satisfied with it. However, AT make some pretty well regarded, more expensive models as do Ortofon, so this might be a way to go which doesn't involve altering your turntable. You can then, still upgrade the tonearm later on when funds permit, knowing you already have a good cartridge to put in it.

I hope this helps you.

Rge Spares by SoundsSupreme

Hi Nick,

Have you tried a Trans-fi Terminator T3 tonearm? I have seen a number of them used on Technics 1200 (check youtube and Vic's customer corner). See Dave Garretson's detailed review on AudioAsylum.

Johnny I had already seen that review, thank you. I think i read it in one of your others posts. It is one of the things motivating me to go along this route.

In the passed I had tried the Ortofon 2M blue, it wasn't bad for the money but the Benz Glider was a big improvement and I am not going back to a MM cartridge. Although the AT150 has always intrigued me. As for the SME M2, I do not know how much better it could be from the stock tonearm but by the looks of it the difference would appear marginal. If I am going to upgrade I want it to make a big improvements. Finally if I up grade the arm and decide thereafter to upgrade the turntable I will have a high quality arm on which to build.

The trans-fi tonearm definitely looks amazing, it would be fun to try. But it also looks very complex and that something I am not ready to own.