I bought my Landmark from Etienne about six months ago (with Gary going 'Go on Paul' in the background) - I hadn't heard about Tech21 until I saw a little advert in Bass Player about nine months ago.
Have to say that it's hands down the best bit of kit - amp-wise- that I've ever owned. For the money, I simply can't fault it. It's got whump, drive, power and versatility in equal measure. Build quality is great. Granted it took a bit of tweaking to get the sound I was looking for, but now it's simply a case of plugging in and I'm pretty much set to go. For the record, I'm running mine into Ashdown enclosures (a 4x10 and a 1x15).
While I'm sure there's better amplifiers out there; it's like hi-fi; it's very easy to achieve a 6.0 or 7.0...hell a Laney or Behringer would probably score this, but it's when you start throwing big money at combinations of amps and enclosures that's when you start scoring extra points.
I can't believe [i]anyone[/i] would rate this 6.5/10. I'm also a bit surprised you used it on [i]many tours[/i] over [i]a few years[/i] if you thought it was mediocre. I know we bass players are pretty stubborn, but we do have deep pockets. IMO, if you were so unhappy (which is how your review reads), then you should have chopped this in some time ago and gotten something else.
Sorry!
P