I purchased a Tech 21 Landmark 600 used approximately 1 year ago. At the same time, I bought an Ampeg 1540 cab that the guy was running with the Landmark 600 head. My band is blues/funk/classic rock based. We just retooled and will be gigging again soon. Forgive me if my recollection of my rigs sound is a little vague. I play a Tobias Killer B 5 string (love it!!!). Fingerstyle, with a little snap/slap. I like the sound options of the amp head (for the most part), and it can nicely emulate a tube amp. I don't run any effects thru it (why bother), and have the foot switch that can switch between the 2 channels. Many times I run both channels at the same time (only available with the foot swith - which is sold as an accessory), giving me my own sound. I have gigged with it in small/medium clubs, and I cut thru just fine. I will also run it direct to the board for a better mix out in the audience. My biggest concern/frustration with the rig is that I get a big boomy bass (almost marshmallow-like, which I hate). I am trying to work with different settings, like playing my bass passive rather than active, tweeking the bass/mid settings, etc... I love that air-moving, move your shirt bottom end, while still being punchy and full. I don't know if the problem lies in my amp settings, in my cabinet, which is a 4x10 and 1x15 combo, and a beast at that (rated for 1200 watts?!?). The head seems punchier thru the Ampeg SVT 410HLF. I have the tweeter off on my 1540, as the amp along with my bass kicks a ton of highs (tech 21's 410 has no tweeter for that reason) I go into Guitar center, and play my bass thru the Ampeg SVT Pro 4, and the 410HLF cab, and love the sound (in the store that is)... so I am struggling. I like the setup I have ( tho I must ge a glutton for punishment - as my rig weighs a TON), I just seem to have a problem getting it dialed in to "my sound". I actually love a latin punchy sound (Santana's "Smooth"). I have also been getting some hiss noise... will try to figure out whats up with that. As I gig more with it, I will try to write another post. I just came across this site today, so I thought I would throw in my 2 cents.