The Flextones and Spiders aren't the cream of the Line 6 crop. The Vetta line is pretty decent, but not as good as the Johnson Millenniums - I'm biased!
Even a really good modeler has it's limitations, and I've yet to hear a truly dynamic, breath robbing, high gain thumping gank from any modeler. That can all change if the amp is mic'ed and EQ'ed right through the PA.
The preset patches on any modeler I've ever tried are basically a joke and serve as simple starting points. I've spent a considerable amount of time tweaking my modelers.
And sometimes, modelers just might not be your cup of tea. Good luck on your quest, Jimi.
Guitars: 2008 Gibson SG Classic, 2006 Gibson Les Paul Standard LE, 2002 Gibson SG Supreme, 2001 Gibson Les Paul Studio Plus, 1996 Les Paul Studio Gem, American Deluxe Double Fat Strat, Bluesville "Super" Strat Copy, MIK Fender "Limited Edition" Tele, JD Bluesville "Night Pilot", Yamaha AES 820, Steinberger Spirit GT Pro, Taylor 355CE, Ovation 1897 Adamas, Ovation CC057 Celebrity
Amps: Axe FX centered rack rig, Mesa 4x12 cab. Germino Club 40, Johnson JM150 Millennium, Johnson JM250 Millennium, Gibson Titan Medalist Frankenstein.
Effects: Tonebone Trimode, EH Holy Grail, Boss CH-1, Dunlop Crybaby Classic, Framptone Amp Switcher, THD Hot Plate, Yamaha AG Stomp Acoustic Processor, Boss BCB-60 Pedal Board.