I have been eyeing the RG3 5 for a while and pulled the trigger about 6 weeks ago.
I have used the bass on several gigs and recording sessions, none of them metal.
The Darkglass preamp sounds wonderful, but the magic is the bass. The B and E string sound ridiculously true and clear in the fundamental note the instrument produces.
The bass with three pickups approximates Pbass, Jazz with both Pickups, Jazz in the bridge position, and Stingray single humbucker using the stock selector. I can't imagine wanting more choices but a replacement selector gives you a couple more, should you need more. These are not metal sounds. These are electric bass sounds we have come to treasure, only better because of how the bass resonates.
Now, if you want metal or rock sounds, add some overdrive, whatever kind and flavor you like, and this bass instantly sounds like the Nolly Getgood demos you hear so often. That is available without trouble.
In short, very versatile bass for any genre and noticeably clearer and stronger fundamental note clarity than you are used to hearing. Whether you are playing Jazz, Gospel, Rock, singer-songwriter music, or death metal, I think you will be blown away by how well this bass works for any of these genres.