RazorPlay
Member
Feather Artist Club or KAI Captain. Doesn't get more aggressive than that! 
IME much depends on the blades. If using a mild razor, then sharp blades are a must (eg Feather) and discard them early (1-2 shaves) before they lose their edge. If using an aggressive razor, then smooth blades are a must. It can all be managed though - when I use my Artist Club with Feather blades (an extreme combo of both sharp blades and aggressive razor), the first couple of shaves are fine if I just go with the grain (for a nice DFS) but going ATG (for an attempt at BBS) will most likely result in irritation or other damage. But shaves 3-15 are great after that - the blades smooth out nicely and are still plenty sharp enough for an ATG BBS. And shaving with a knife is great...
I'm also a fan of Fatips in nickel finish but I admit the blade alignment could be better - doesn't take much to fix though and the brass / price combo is hard to beat. But only with a mild blade unless you like being extremely careful (Lord blades are great in my Fatip).
So whatever aggressive razor you buy, make sure you try a bunch of different blades in it. What works in some razors may not work in others and vice versa. So far, I've managed to find a blade for every razor - even that Merkur you have. For that Merkur, it was only Personna Lab Blues that would give me an excellent result and those blades in any other razor result in a horrible mess for me. So I'm of the belief there is a blade for every razor for most faces - you just have to find it.
IME much depends on the blades. If using a mild razor, then sharp blades are a must (eg Feather) and discard them early (1-2 shaves) before they lose their edge. If using an aggressive razor, then smooth blades are a must. It can all be managed though - when I use my Artist Club with Feather blades (an extreme combo of both sharp blades and aggressive razor), the first couple of shaves are fine if I just go with the grain (for a nice DFS) but going ATG (for an attempt at BBS) will most likely result in irritation or other damage. But shaves 3-15 are great after that - the blades smooth out nicely and are still plenty sharp enough for an ATG BBS. And shaving with a knife is great...
I'm also a fan of Fatips in nickel finish but I admit the blade alignment could be better - doesn't take much to fix though and the brass / price combo is hard to beat. But only with a mild blade unless you like being extremely careful (Lord blades are great in my Fatip).
So whatever aggressive razor you buy, make sure you try a bunch of different blades in it. What works in some razors may not work in others and vice versa. So far, I've managed to find a blade for every razor - even that Merkur you have. For that Merkur, it was only Personna Lab Blues that would give me an excellent result and those blades in any other razor result in a horrible mess for me. So I'm of the belief there is a blade for every razor for most faces - you just have to find it.