So cool that Hollow is back after almost 20 years! It's basically Andreas Stoltz's solo project now, as he is playing everything but the drums, but he always did wrote everything, anyway.
He kept basically the same formula, power/prog metal with high vocals and heavy, crunchy, meaty guitar riffs. A lot of melody, but very different from most power metal bands, it's a lot closer to early Queensryche (but heavier) than to power metal, actually.
The only slight complaint i have is about the drums, the drummer from the first two albums had a very distinct sound and style, with lots of groove, and now the drums are more "standard" metal drums. Not bad, but not as distinctive.