Open comb DEs are not that different from safety bars, but there are huge differences in head designs between most safety bar DEs and open combs. Vintage Gillette OC DEs are interesting because that is the way DE shaving began with a Gillette Old type OC razor in about 1904 (?). The old type is very finicky about the angle and was pretty much the replacement for the straight. I do not particularly care for the Old type Gillette. Then came New Improved Gillette. That razor head has zero blade exposure and a huge gap between the razor and the comp. This may not make sense, but that razor is pretty aggressive and extremely sensitive to pressure. It feels mild, but cuts very aggressively, especially if not careful with pressure. Angle on the New Improved is pretty forgiving, but you'd do best to keep to that 30 degrees or less on any DE for best results. Then came the Gillette New, which had two versions Long Comb and Short Comb. Short comb is pretty mild and has little to no blade exposure and the blade gap has been reduced compared to New Improved. The long comb New has a healthy blade exposure and pretty good blade gap and as a result is a fairly aggressive open comb. Way more aggressive than the 34C, but not crazy like Muhle R41 (2011 version). I think one of the best DE razor designs has to be New Long comb. If you learn how to use it with good angle and pressure it is actually one of the best DE razors out there. And it's fairly cheap and easy to come by. The handle son them were not always great and got cracks in them, so a nice heavy stainless handle like Ikon Bulldog or Weber Bulldog would be a good choice for replacement, but the New Long Comb head is a really good moderately aggressive head. If you shave with a straight you should have no problem enjoying awesome shaves with it. Just mind that angle and you actually feel the blade edge on your skin. This, IMO is the key difference between a good OC DE and the safety bar one. Another really good OC DE head is Cadet also sold by RazoRock brand and Matador. The full razor is about $20, is made in India and is of pretty good quality. The head design on that OC is a bit more aggressive than the Gillette New LC and it shaves great, again, if you mind that angle and pressure. The feeling of an OC is a bit different as is leaves more soap on as you move it along the skin. It also does not clog up easily. The biggest difference is the aggressiveness of most OC heads vs safety bar ones. 34C is pretty mild. If you want to experience a really good old OC razor definitely check out the Gillette New LC. They are generally sold for around $20 or so on the 'bay. Make sure all the teeth are straight and the handle is not falling apart. If it's a ball end handle and has cracks, it's no big deal and that can be stabilized with epoxy. Or the handle can be tossed and replaced with better modern handle that will add nice weight to the setup. I have been using New LC on top of the Ikon handle for a while and enjoying it greatly. I've also been using a RazoRock Little Bastone OC with great results. Pretty much my only remaining safety bar razor is vintage Merkur Progress, which is my favorite safety bar razor and is pretty much responsible for giving up on the rest of the safety bar DEs. As in everything else, you just need to try the different OCs and see for yourself. Most people begin the OC journey with a New LC because it is so well designed. Even 90 years later, it still holds its own against the modern DE razors.