I would say that his assessment of her ability to sing at least some of the Wagnerian rep is right on the money. There is a wonderful RAI recording of Oberon, only released on vinyl as far as I know, that certainly would bear this out. "Ozean" here exposed as "Mare, superbo mare" is my all time favorite version of the aria.
And Reiza's "Prayer" is one of the most stunning pieces of singing you will ever hear. Not less impressive than her "O re dei cieli" from "Agnese di Hohenstaufen". Those of you who would want the Oberon can at least get the "Ozean" on a Lyric CD that contains a lot of other great stuff, including Ernani, Aida, Agnese di .., Wally etc. Magnificent singer! My only caveat to James' post is that the opera is available complete on several labels and I think it is certainly worth the additional investment. I've been hoping that this would show up on CD for a long time. It had one incarnation on LP many years ago. She is just about the end on it. The opening aria is along the lines of the Hohenstaufen aria, for which she is so famous. The voice just pours out as line after line of upper middle singing is tackled with the greatest of ease. The "Mare superbo Mare" is superbo as well, with a thrilling top C. Finally the repose of the prayer in the last act is magnificent. Picchi is a fine Huon and tackles the tessitura with no problems. The sound is fine if not of studio quality, but it is at least as good as was on the original LP, no mean feat in the face of some recent transfers on other labels. You must own this if you have any regard for Cerquetti. Even if you don't, you might get the message from this performance.