Thanks very much for your helpful replies, Jon and Fllg, I appreciate your having taken the time and trouble to give me your thoughts.
Jonathan Tait wrote on 05/16/15 at 06:14:33:

I didn't explain myself as clearly as I should have done, but what particularly bothers me about the ending under discussion is being steered into it by lower rated players as a risk-free drawing attempt rather than by stronger players as a winning attempt, but I take your point, it shouldn't be too difficult to defend. Thanks for the suggestions of alternative ways of playing the 4.d3 line. I was aware of 6...d6 and felt that locking the dark-square bishop in like that wasn't really in the spirit of the opening - or at least not in the spirit of the way I was hoping to play it - but I'd not considered 4...Nf6 at all, and I shall certainly give that interesting suggestion a look.

Fllg wrote on 05/16/15 at 08:12:40:

You're absolutely right about this, but the line with 5...d5 rather than 5...Nf6 gives plenty of scope to outplay a weaker or unprepared opponent, so I'm less concerned about 4.Nc3 than 4.d3. You're right, too, that the Schliemann seems to be a drawing weapon at higher levels, and I was a bit surprised that the repertoire offered by Collins on his DVD appears to be based on precisely these drawish lines - which is why I'd still be interested to hear opinions form anyone who has actually watched the DVD.

Seeley wrote on 05/15/15 at 20:52:11:


I wouldn't be particularly worried about defending that endgame, and I can't imagine any of my (much lower level than Carlsen or Topalov) opponents taking this on as a winning attempt for White either.

But anyway, you don't have to play the 6...Bc5 line. Either 6...d6 or 4...Nf6!? is rather more fun, even if the latter is certainly inferior.