I've used a number of Givi cases and just like my V46 the best out of all of them. It's the largest case I've tested that doesn't really cause interfere with wind flow. I had the Maxia 55 and it was great for the space, but I just didn't like the view back from my mirrors (blocked too much) and I could definitely tell it was affecting the way the air flowed and I didn't like that. I also had the E52 and I liked that one a lot, but I sold it with my '13 FJR.
The V46 is still a good 46L of space and it doesn't interfere with my view back in the mirrors and I don't feel any difference in the air flow. I also had/have a small Shad, but I found that I really liked the quality better from Givi and that SR357 rack is the answer for my rear subframe support.
For grins and giggles, I think I'm going to check out the Givi WL901 Weightless trunk, though it's not really lockable. I'm looking to use that as a day trip trunk and save a little space and weight for those days. But it doesn't have the weather protection like a normal trunk. If I were to look at Shad again, I would look at the SH58X model, but that's not cheap and I still don't like the subframe support on that compared to the SR357.
Maybe this helps, maybe it doesn't, but it's my 2 cents worth - LOL.
2008 FJR1300 (current)
2013 FJR1300 (sold)
2007 Goldwing (sold)
2005 FJR1300 (traded in)