I have followed the birth and development of the 300 BO from a hobbyist perspective. It isn't a caliber I've found a niche for personally, but it is still an interesting critter to read & learn about. Invest in? Not right away. Suppressors in Kalifornistan? Chortle, chortle, guffaw, guffaw.
As a nation we have spent 60 years with the 223 Rem/5.56 x 45 NATO. 3 generations of soldiers, sailors, Marines, and airmen have given the caliber a thorough test drive. I think civilian/citizen users have passed judgement as well, and it has been largely positive. Once controlled-expansion hunting bullets are added to the the caliber's features mix it becomes a very useful hunting tool, though care must be taken regarding bullet selection--most .224" centerfire commersh offerings tend toward varmint venues. Game bullets for critters larger than coyotes......Nosler Partition and Barnes often get the call.
Like the 30-06 and 308, all manner of wildcatting mods have followed in the 223's wake--to both the cartridge and its OEM housing the AR-series rifles. The 300 BO and others follow in that tradition. For now i am content to remain in the gallery looking on. It appears that my catheters in the right shoulder are getting removed soon, and I can think of no better way to commemorate my survival than to have another upper half built to fit atop my Aero Precision lower.