I've read accounts of native Italian speakers who always use [ɾ].
You're a native Italian speaker, right? How do you pronounce <r> & <rr>?
Short answer: like most Italians, I use the alveolar trill /r/ (geminate or not).
<rr> is just like in Spanish, while a single <r> is a single, "one-contact" trill. However, here are a few remarks for a more elaborate answer:
- some texts classify what I called a single trill as a "tap/trill" (perhaps suggesting that both realizations are valid – I am confused now)
- the third paragraph of this document
(which focuses on a very specific subject that is beyond our scope, but this one paragraph talks about Standard Italian) suggests that some scholars consider a third realization of <r>, too, besides the two trills: the tap
- I believe that some speakers (including but not limited to the Veneto region) do use the tap /ɾ/ with a certain consistency, for example in inter-vocalic position