I'm no expert, but these are things I personally noticed:
Image 1:
Red: BPF has a much thicker chamfer than ARF. ARF is more gen like
Green: BPF has slightly deeper SEL height; BPF is more gen like (?)
Yellow: BPF has smaller bezel "crinkles" than ARF. ARF is more gen like. Also, BPF uses 6-digit Bezel assembly (From what I hear). Also, BPF bezel insert is not compatible with ARF or Gen without thinning the bezel insert.
Blue: BPF has crisper and thinner datewheel font than ARF. BPF more gen like.
Image 2:
Red: BPF bracelet comes with polished sides; They messed this up by switching 16610 and 16600 bracelets. ARF is more gen like.
Blue: BPF bezel is thicker than ARF. ARF more gen like.
Green: BPF has slightly thinner caseback than ARF.
Image 3:
I know there is a confusion about SH3135 v2 vs VR3135, and factories merging etc.
But the movements in ARF and BPF are definitely different (according to Trusty's images).
Red: BPF shock absorber setting has a slightly wider mouth than ARF.
Green: engravement quality is much different on BPF than ARF. BPF looks like it's more deeply and crisply engraved than ARF.
Blue: Finishing is different between BPF and ARF.
Maybe rumors are true and SH/VR are merged. Maybe the Trusty examples are just different 3135 batches from same factory. Or perhaps the rumors are wrong. But at least from Trusty's images, BPF looks like a better movement quality than ARF.
These are just stuff I noticed. I know crownguard shape is something a lot of others point out, but I personally can't really tell much of a difference (I'd be open to someone explaining the difference).
I went with BP due to price difference, but having mixed feelings now.
ARF better in some aspects, BPF better in others. Also the possibility of different movement qualities.