I am not sure what it the current verdict, but some top GMs used it occasionally as a surprise weapon.
The downside is that any good player playing the Petroff will be prepared for the most critical lines, so you do have to know a lot of forced theoretical lines to avoid ending up worse after the opening. Yes, they usually involve c5 dxc5 Nc6! at some point ;)
Also, you have to be on a constant look-out for various piece-exchanging ideas from Black, as steering the game into an endgame in one way for Black to fight for an advantage..
I also play Cochrane in Blitz.. sometimes it works, sometimes it doesn't, but it is fun to play.
On the other hand, main lines of the Petroff are also not as dull as people think and there is a lot of room for tactical play. If, on the other hand, you really wish to avoid the theory there, you could always consider the lines with Nc3 after the Black takes on e4...
After the series of moves 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 instead of the expected 4.Nf3, I now play the brutal 4.Nxf7!?, the Cochrane Gambit, which totally unbalances the game. I now play it against all levels. I have yet to beat a titled player with it(although I drew a CM in OTB). What do you think about this opening? If we look at the imbalances created, Black has a piece for 2 pawns, a material advantage of slightly more than 1 pawn. However, he has lost some king protection, and will have to spend some tempi to get the king safe artificially castling. Another imbalance is the crushing 4 on 2 pawn majority on the kingside. Unsurprisingly, a major idea for white in many lines is to attack with f4, and keep advancing, adding in g4. After 4...Kxf7 5.d4(best) it looks like a speculative sacrifice, but that white has huge compensation with his pawns, majority, and ease to develop and attack. Indeed, white wins about 45% after 5.d4, and draws a lot. Black wins a bit more than 30%. Looks good, but I recently lost to a B player in OTB after he responded with the best 5...c5!. What do you think about the gambit?