Had a DUAL 701 with upgraded (heavier) wood base from a modder in the Midwest (can't remember his name, but he did great work and he's a woodworker by trade so the new base was well made).
Added Plast-i-clay to that base and found the effects were so-so in benefit. It didn't hurt the presentation, but I strained to hear the benefits whereas in certain decks the benefits are soooo obvious.
The failing on the 701 was primarily the arm - it's a trapped energy mess (which includes that DUAL proprietary plastic headshell). The biggest upgrade was constrained layer damping dots - experimenting with positioning - and I had either plast-i-clay or damping dots at the base/pillar, too.
It ended up singing once I did these things. At the time I had like 5 tables so I sold it off to a chap in Taiwan who I hope was very happy with it. The 701 had a terrific/strong direct drive motor (pre-quartz era), but because it floated, had an expansive soundstage like a really good belt drive (but with more exact timing and better sounding piano and other matters that DD can often do better than inexpensive belt drives)
Experiment - it didn't cost you much. It's the best way to learn. Every aspiring vinylphool probably needs a junker or two table to dial in your upgrades: some work, some don't, some are too costly or time consuming, etc. I had two junkers that I did near everything I could think of too....total cost was like $150 between the two tables (and I even got a preemo ADC XLM II cartridge body from one of them that I still use with NOS cantilever in it)
Cheers, John