We've had posts on under-rated and "awful recordings" that are actually quite good but I have had some recent experience of acquiring some "classic" recordings that disappoint for various reasons.
First, I added to my 12 strong collection of Marriage of Figaros by buying the classic Solti recording that has always been outside my price bracket. I found it a strangely hollow experience. It's beautifully recorded, beautifully sung and lovingly conducted. Yet for me that's it and the sheer perfect loveliness never gives way to a living underbelly that involves you in the motivations or experiences of the characters. I much prefer Oestmann, Gardiner, Jacobs and Davis. I have been let down by Solti before - his Ballo in Maschera, Carmen, Traviata and second Falstaff were all sold soon after purchase. I do still love his Fidelio, Aida and Zauberflote though.
Second, I got hold of the Von Karajan Madama Butterfly with Pavarotti and Freni for the first time. Wow. How bad is this? Sluggish temi, overbalanced orchestra drowning out any attempts Freni makes at sublety and a rather loud Pavarotti. I love Karajan's Boheme, Tosca and Turandot but was very disappointed in this. I prefer the earlier Karajan with Callas and the Barbirolli or Leinsdorf recordings.
I began to think that perhaps I had collected too much and that it wasn't the recordings but the sheer volume of versions I had that was at fault. So I listened again and came to the same conclusions.
One thing I did wonder was whether DECCA had anything to do with the clean, sheened and ultimately lifeless veneer on these recordings. Have my tastes for "perfect" studio conditions changed as more and more opera is recorded in association with or "as live" performances?
Any other "classic" recordings I should avoid or let downs that you have had would be gratefully received.