FWIW, I've had most of the Italian brand pens; Aurora, OMAS, Delta, Visconti, Stipula, Tibaldi, and Montegrappa.
Overall, all of the pens listed have been very good, but the one Visconti I had needed some feed cleaning first as I recall.
After having about 8 plus Delta pens, I would rate them as very high quality. It's unfortunate that Greg has had such issues with them as that has not been my experience with them. However, I'm not discounting the issues he's had.
From reading the various forum sections the past several years here, you can find someone for most pen brands that has had negative experiences with that brand, while others experiences have been positive. Just the way it is.....unfortunately. It's clear that some pens leave the manufacturer without getting a complete QC check and adjustments if needed.