One needs to put one's brain in hibernate mode, forget everything one knows about music history and performance practice, and then this becomes at least a semi-rewarding experience :) Yes, it could be called turgid, even shocking, but possibly only in the way a swimming pool is shocking when you jump in cold. Give it a little time--the water may be fine. Grit your teeth during the overture, and during Ilia's opening declamations. Those are the worst parts, and things do improve. It is much better when Pears enters. After all, he IS singing English, his specialty. (None of these apologetics can save him singing German or Italian, however--that is utterly hopeless.)
This TV production is from 1970 and the color picture is accordingly rich and beautiful. The sound however is below average for the era, but still ... twiddle the knobs, turn the bass up a little, and get acclimated. This is a fully traditional production, actually very pleasing in that regard. Traditional excepting only the tasteful English translation, and possibly also the even more tasteful short skirt worn by Idamante (son of Idomeneo), played by a good looking young lady ... my goodness, what a great set of legs. Did ancient soldiers really wear THAT short a skirt????
I am also happy to report that although it is performed in English, subtitles in English are provided. (Too bad they didn't include subtitles for the upper-crust BBC commentator where they're needed far more than anywhere else!)
This is a two DVD set and not seriously abridged, although they did cut Fuor del Mar, my favorite aria in this opera.
I do recommend this recording of Idomeneo, not necessarily because of its quirky merits, but as a document by a musician and composer I truly respect--Benjamin Britten.