I have not yet looked for SPF values in them for summer. I have seen bibs that have it but have not specifically bought them. As for the most comfortable, they are all nice but for summer I have been reaching for the Rapha bibs. They have enough padding and light enough while still breathing well. Given the level of heat and humidity, the cost of the rapha core bibs are roughly 2 bibs compared to 1 bib for castelli/giordana/etc. So given the level of sweat and work, it allows for more rotation of bibs and less washing/wearing. Plus, the cargo core versions are, to me anyway, pretty game changing.

Me too.

Any deals on some decent bib shorts these days? I have a great pair of Assos shorts I got from the Factory Outlet a few years ago, but nothing in Medium right now. A lot of folks seem to like the Castelli Free Aero Race.
I'm in Canada, I'm case it matters.

Autumn seems to be the best time for deals in cycling apparel. Winter can be cheaper but selection is worse. Spring and summer usually are the most expensive periods. But COVID-19 can change all of this as in many places bike riding is prohibited now.

Their customer service for any warranty item is perhaps the worst in the industry based on my experience. I avoid all of their products based on how I was treated and place my loyalty with Assos, PI, Castelli, Rapha. Just my two cents...

Of course, and the Spring Bike Show in Toronto was something I chose to avoid this year given it happened just a week or so before lockdowns began.

Though spring/summer should be better for knickers, tights and/or longsleeved apparel. eg. Castelli Sorpasso bib tights (same chamois as Free Aero Race shorts) are $114 at SteepAndCheap