I prefer open combs because of the flatter head geometry.
I like the OLD style and the clones of the OLD.
They might look the same but they all behave slightly different.
Some are milder than a 70's copy of Penthouse and some are proper Putin.
Just noticed you have Souplex or Big Ben there (same razor, different names), I love that razor and as OCs go it is quite mild. I recently received a Big Ben from another forum member and I'm looking forward to trying it out next week. I'm debating putting my Souplex in my travel kit, I don't shave daily on holiday, but I would be gutted if I lost it...
The difference is nil. Open combs cost more to make, and are more easily damaged during production. This is why manufacturers started to produce closed comb (bar guard) razors starting in the late 1930's.What is the difference (other than the physical aspect) and what are the advantages?