I had high hopes for this series despite having read some of the criticisms. Two episodes in, however, and I have to agree with several negative observations: the actors are way too old and utterly charmless; the dialogue is stilted and the long pauses in conversation make Tom, Dickie, and Marge all seem clinically depressed; there is no plausible explanation as to why Tom was recruited by Mr. Greenleaf in the first place; Tom's character is so awkward and careless that it's impossible to believe he ever had any success as a con man; Dickie and Marge don't fare much better in the personality department--are they together because they are the only Americans in town?
The only critical comment I don't agree with is the B&W photography, which seems to add to the beauty and period authenticity.
Both previous versions, 1960's Purple Noon and the 1999's masterful The Talented Mr. Ripley gave us actors who oozed charm and made it clear why the various characters were drawn to each other--and why Tom was able to push the limits with his actions and increasingly improbable explanations. I'll try to keep watching, but, at this point, I'm not expecting a Cate Blanchet (brilliant in 1999) or Philip Seymour Hoffman (good but miscast) to come to series' need for a shot of adrenaline. Maybe a trip to Cortina IS what they need to shake off the doldrums.