T-55(A/AM-1/AMD-1) APDS or APFSDS?

I picked up the AM-1 today with the pack sales starting (really original choice I know) which is a bit ahead from where I am on the Russian tree currently so I haven't used this gun and this ammo, of which there is frankly a mind boggling amount, more than usual.

I opted to not use the HEATFS as the main round despite having the most pen due to the classic HEATFS shenanigans and general inconcistent behavior they have. Which leaves us with the APDS and the APFSDS. I played a dozen or so matches today and used the APFSDS because it should be better than the APDS, right? Well after a few mysterious bounces at angles and distances that were not at all extreme and I noticed that the stats between the APDS and the FSDS are nearly identical, with the Fin Stabilised round having marginally higher muzzle velocity and an extra degree for ricochet chances but it's also half a kilogram lighter while the APDS gets marginally better pen by a few mm pretty much across the board.

Going by the stat cards alone, they're identical. But I'm wondering if there's something not on the stat card I should keep in mind, like post pen fragmentation or whatever. I know APDS rounds have a weird tendency of mysteriously shattering for no apparent reason. Basically my question is, is there a reason to use one over the other or is the real question here whether I'm better off using HEATFS over a dart?