There was a similar thread on RT back in the day. Someone asked "When will someone come up with a completely NEW amplifier design?" Referring to the big 3: Fender, Marshall, and Vox. We discussed, and most people agreed that no matter how good the amp, at the core of MOST boutique designs, is a Fender (EQ before gain), Marshall (EQ after the gain stages), or Vox (Class A EL34 type). Sometimes, designs are hybrids of these two. When you think about it, there's 3 elements: Gain stages, EQ, and Power Amp. Until someone comes up with something new, besides this, that actually SOUNDS good, I'm not sure if they're going to "leave a mark".
Egnater makes great stuff, no doubt. They were wise enough to take a look at the amp market, and see the big gaping hole in the middle. NO ONE was making boutique-sounding, affordable amps that were right around the $1K mark. And no one was making boutique lunchbox amps at the $500 mark. And no one else had a partnership with GC. They struck at the right place, right time, right product, right price. A complete winning combination. People were tired of Fender Hot Rod deluxes. People were tired of Marshall Valvestates. People were tired of Line 6. And people couldn't afford Boogies or other boutique-y stuff. In comes Egnater, and they were the "other option" that people had been hoping for!
Again, great amps. I'm planning on buying a Tweaker. I've owned a Renegade and a Rebel. But I think their popularity is based on filling a hole in the market with good sounding, cleverly priced products - and not necessarily "game changing" designs.