If you're not looking to retire for ~30 years, is TRBCX a safe fund to go 100% into? My only concern would be Puglia retiring; however, other funds at T. Rowe as well as Fidelity and Vanguard have carried on the success of the original PM without much issues long-term.
It is a good fund, but why put all your eggs in one basket? Even if you want to go 100% equity, why not have more diversity, even among all US stocks? There are other good funds, which would give you more market coverage.
Being 100% equities at your age is very smart and TRBCX is a great choice. TRP does a wonderful job of transitioning PMs, which is not something Fidelity does particularly well. In general, there is way too much PM shuffling at Fidelity. You only need a couple of good funds in your entire portfolio to be successful. Don’t be a fund collector like nearly all people on these forums. Know what you own and why you own it. And then continue to follow, monitor, and read everything about it (Annual Reports, etc.).
I don't think I would make this my only fund. You're ignoring small/mid caps. As well as international. And I even like some bonds for diversification. Have you done some reading on asset allocation & diversification?? Plus this fund is not exactly slim & trim with 75 billion in assets. If you want a growth fund, this is not a bad choice. But I wouldn't make it my only fund.
TRP are generally very good at closing funds if they think keeping a fund open is detriment to its performance. Since this fund is open, they must think current AUM is not a limitation to its performance.