Well, the OLIVs are supple and have a good feel and the EPs don't actually exist. They're a myth like the unicorn or yeti.
O.K., here's a partially better answer. I played each of these strings at fairly different times, with months of seperation, so take it for what it's worth. They all share a certain suppleness, bounciness that I really enjoy about them, which is one of the main reasons for watching this thread. I would guess that the EP is between the OLIV and Obligato in gauge. The EP reminded me more of the OLIV than the Obligato, but I really think that if I had had them on one after the other, the EP G would have paled to the OLIV. I don't think it will have the presence, but it's a good proximity to it. Better than anything else I've played.
I think that the OLIV is fairly unlike other plain gut strings that I've played in sound and feel.
The Obligato left me with an impression of being thinner with much less presence than either of the other two.
Tension, is a scientific measure that I can't really comment on, but Pirastro might if you emailed them. I can only give you my impressions of feel.
...but I'm not actually thinking about strings anymore so I don't even know why you're talking to me right now.
-tk