I don't have a modeling amp, but I think I may have some insight. I believe there's a tendency by both players and builders of less expensive amplifiers with many convenient features to adress bedroom level and digital home studio playing conditions over live conditions. That isn't to say that digital amps don't have watts. I think it's more about the preset EQ parameters and the amps being idealized in this aspect for quieter playing rather than louder playing. Imagine that mid scooped tone that fills up more range in your ears at lower playing volumes.
Ok, I'll just say it out loud. The digital amp genre does sort of cater to bedroom wanker tone. And yes, that EQ balance is easily swallowed up in a live band mix. You can try turning up the midrange if it's even in a suitable band for a more natural sound. I had 50W (called a 60 actually, but you know...) Peavey tube combo that sounded great at bedroom levels but just couldn't cut through the mix in a live setting. It was definitely geared more toward the uber gain preamp bedroom wanker tones and I imagine the trouble with digital modeler combos could be similar.
Also, I wouldn't be surprised if most of the stock speakers used in these amps aren't as efficient as the ones we buy for out tube amps. Since modelers need a more flexible and balanced pallet of frequencies to get good results from all the digital images I would expect less pronounced peaks and resonance characteristics. You might get more useful live tones for many digital patches by changing to a standard high end guitar speaker rather than the stock one deemed more suitable for modeling. Though you may not like it with all the offered patches.
JM2C without the benefit of much actual experience.