The GT-6, sounds great! You will find people fighting over which one sounds better POD or GT-6. I haven't compared them personally.
I mentioned the GT-6 users group. If you subscribe to the group there are sound samples and detailed info.
I favor the "Hi Gain" & "Big Rectifier" sounds for distortion from this unit. Like almost anything else you will need to tweek to your needs or depending on your guitar. It allows for 2 additional expression pedals as well.
I also like the knob features. Simply tweek and "write" and your saved. This unit has many cabinet simulations as well as customizable. There are selectable output levels that effect sound spectrum. I prefer the "line/phones" =biggest sound-IMO.
You must adjust to your performing environment and this unit makes it easy.
I've had mine 3 or 4 months and have not had a chance to fully explore this unit. I am not a spokeman so please go try it for yourself.
Here are the detailed effects, preamps, etc:
Effects
= Preamp/Speaker
= OD/DS
= Delay
= Chorus
= Reverb
= Wah
= EQ
= FX1 Group (one effect per patch)
Compressor, Limiter, Acoustic Guitar Simulator, Pickup Simulator, Tremolo, Slow Gear, Feedbacker, Anti-Feedbacker
Defretter
= FX2 Group (one effect per patch)
Phaser, Flanger, Harmonist, Pitch Shifter, Pedal Bend, 2 X 2 Chorus, Pan, Vibrato, Uni-V, Short Delay, Humanizer
Ring Mod, Slicer, Auto Riff, Guitar Synth, Sub Equalizer
= Noise Suppressor
= Foot Volume
= Master Patch Level
= Master BPM
COSM Preamp Types
= JC Clean
JC-120: Roland JC-120
Jazz Combo: Roland JC-120
Full Range: Flat response amp (e.g., a keyboard amp)
= TW Clean
Clean TWIN: Fender Twin Reverb
Pro Crunch:
Fender Pro Reverb
Tweed: Fender Bassman 4x10" combo
= Crunch
Crunch: Crunch sound with natural distortion
Blues
Stack Crunch: Crunch sound with high gain
= VO Combo
VO Drive: Vox AC-30TB drive sound
VO Lead: Vox AC-30TB lead sound
VO Clean): Vox AC-30TB clean sound
= Match Drv
MATCH Drive: Matchless D/C-30 left input channel
MATCH Lead: Matchless D/C-30 right input channel
Fat MATCH: Matchless D/C-30 with modified high gain
= BG Lead
BG Lead: MESA/Boogie combo amp
BG Drive: MESA/Boogie with Treble Shift Switch on
BG Rhythm: MESA/Boogie rhythm channel
= MS Stack
MS1959(I): Marshall 1959 input I
MS1959(I+II): Marshall 1959 inputs I and II connected in parallel
MS HiGain: Marshall with modified midrange boost
= R-Fier
R-Fier Red: MESA/Boogie Dual Rectifier lead channel
R-Fier Orang: MESA/Boogie Dual Rectifier rhythm channel
R-Fier Vint: MESA/Boogie Rectifier with Vintage Switch on
= Hi Gain
SLDN: Soldano SLO-100
Drive Stack: Drive sound with high gain
Lead Stack: Lead sound with high gain
= Metal
5150 Drive: Peavey EVH 5150
Metal Stack: Drive sound for metal
Metal Lead: Lead sound for metal
= Custom
Custom1: Slot for saving a user-specified custom preamp setting
Custom2: Slot for saving a user-specified custom preamp setting
Custom3: Slot for saving a user-specified custom preamp setting
COSM OD/DS Types
= OD/Boost
Blues OD:
BOSS BD-2 pedal
Turbo OD:
BOSS OD-2 pedal
Booster: New booster that works well with COSM amps
= Dist
Distortion: Basic, traditional distortion sound
American DS:
Proco RAT pedal
GUV DS: Marshall Guv’nor distortion pedal
= Classic
OD-1:
BOSS OD-1 pedal
T-Scream: Ibanez TS-808 Tube Screamer pedal
DST+: MXR Distortion+ pedal
= Fuzz
'60s Fuzz: Fuzzface pedal
Oct Fuzz: Acetone Fuzz pedal
Muff Fuzz:
Electro-Harmonix Big Muff Pi pedal
= Metal
Metal Zone:
Boss MT-2 pedal
R-MAN: Rockman distortion sound
Heavy Metal: Heavy distortion sound
= Custom/External
Custom1: Slot for saving a user-specified custom OD/DS setting
Custom2: Slot for saving a user-specified custom OD/DS setting
External: Slot for connecting an external effects pedal
COSM Wah Types
= CRY Wah: 1970s Crybaby wah
= VO Wah: 1970s
Vox V846 wah
= Fat Wah: Bold wah
= Light Wah: Refined, "no unusual characteristics"
= 7String Wah: Broad range of variations for 7-string guitar
= Custom1: Slot for saving a user-specified custom wah setting
= Custom2: Slot for saving a user-specified
custom wah setting
= Custom3: Slot for saving a user-specified
custom wah setting
Hope I covered it all!