My first attempt at responding to this turned into an eye-glazing manual on vibration control for the Technics.
08-08-11: Stanwal
It would be worse in my opinion. I have had several 304s and never found them bright. On the other hand 2 of my friends have the Technics table and I find them bright. The AT 150 has a reputation for being aggressive on the top end so I would look for something softer in sound.
The succinct version is: the SL12x0 and AT150MLX can be a transparent, dynamic, linear, organic-sounding combination IF you damp the vibrations and resonances in the Technics. Wrap the tonearm with Teflon pipe thread tape, upgrade the mat and headshell, throw out the stock feet and use Vibrapod Cones and Isolators under the turntable instead. Platform it on a thick cutting board and isolate it from below with silicone gel pads or more Vibrapods.
If you do all this, the Technics should be smooth and linear whether you choose an AT150MLX or Denon. I use an AT150MLX to good effect. You'll have a linear enough platform to evaluate downstream cabling and components for further improvements.