I’ll put anything against my boosted blue channel Bogner and the in room will 100% get demolished by whatever’s next to it. I’ve never in my life heard an amp as inspiring or as big sounding as the old iron 101Bs.
Modern gear (minis, IRs, modeling, etc) is great for recording and convenience assuming you have the knowledge to make it sound good. Even then, the live difference is very notable.
For live, IMO, monitors are better for the venue because they have a wider beam meaning it's easier to hear the same sound from different positions. Much like a THX Dolby cinema system. Cabs are very directional and the differences from a full-stack are notable just by walking around the venue. You need a wall of sound to cover everything... or monitors.
Also if you have a 100W and need to open up the master volume for some crunch then you are already probably at a venue big enough to tolerate that and more. Meaning it has a monitor system in the thousands of watts if not tens or hundreds of. So the cab sound is drowned out after the first few rows of people. What can get through is the directional chest thump of a cab which feels different but many monitor systems have subwoofers that also give a thump. Depends on where you stand in the crowd to feel it.
If you don't have to crank the master volume for distortion then a 100W can be feasible such as with an EVH 5150 100W or a Diezel Herbert 180W. You can play those low volume settings anywhere but when you have a 100W and your tone is with the master volume on high (Marshalls for example), then that's too uncomfortable to be around to enjoy. Like a pneumatic drill or an ambulance siren level of volume. Even some gigs are unbearable like Motorhead with their heads on full belt. Attenuation/loadbox are the only way around that in small settings with a 100W.
Gojira uses 100W 5150IIIs through a Two Notes Torpedo Live loadbox. They have one of the loudest stage performances on the metal circuit around. 2x12 EVH IR (Eddie). Two notes have the settings on their site.
The days of 4x12s seem really past. More for show. If you have a big enough room then it can sound great and at rehearsals for the chest thump but a small venue, 2x12 and 50W amps max IMO or even just use the loadbox and monitor out. Choice of cab sims for the environment.
Even some top bands playing high gain metal just have the 4x12s for show and the lead guitarist is using a 1x12 combo behind a screen and microphoned up really well. Yes, it's all-tube not digital, but likely to be well under 50W.
