I have owned a AC 1 in various avtars for close to 2.5 years. To the OPs query is it dark sounding, most emphatically not IME.As Halcro rightly points out you can tweak a TT to optimise its sound in various ways, record clamp, mat, isolation etc.If by dark sounding you mean that the highs are muted or rolled over, its possible to achieve that with the TW by placing rubber dampers under the feet, as I discovered. I had my tone arm, a Talea 2,initially mounted on a wooden armboard. Switching to the TW supplied SS arm mount has led to clearer and cleaner definition of notes almost as if the TT has picked up speed.
I am somewhat sceptical of generalisations, particularly in respect of TTs, that a particular model or brand is bright/dark sounding, given the large variables at play. For example, when you demo a TT at a dealers what is the likelihood of the cart being precisely aligned with a Mint tractor or equivalent ?
The TW AC is one of the truly outatanding TTs available today. I am not saying its the best because there is no such thing. Having heard a pile of different TT setups at the Adelphi in Singapore over the years, I can say that the TW is among the handful of must audition TTs for anyone contemplating a TT at this price point.
As an aside, if you do go the AC3 route, you may like to consider, the TW BN single 3 motor unit as against the 3 separate motors of the AC unit. I am not sure but I suspect that there is not much of a price difference if you order it as a package. Additionall, the battery powered PSU does lower the noise floor though I suspect this is of a lesser magnitude in terms of improvements as the unit runs, at least IME, for less than 4 hrs on battery power before switching to the mains.
All the best in your vinyl journey
Cheers
Pradeep