Help me out! I've been playing Renekton lately and I've been weighing the pros and cons of a Brutalizer vs a BF Sword.

I want to build Renekton with a focus on tanky DPS rather than tanky off tank.

My build so far is something like this: boots/pots/dorans -> phage -> cdr boots -> Brutalizer or BF Sword-> Frozen Mallet

After the CDR boots I want to build another DPS item before finishing Frozen Mallet. It's either brutalizer or BF sword. Which one do you feel is better?

Bruatlizer:
-cheaper
-cdr
-armor pen

But it builds into ghost blade which I will never build.

BF Sword:
-More AD for AD scaling abilities
-Builds into Bloodthirster

But it's more expensive and doesn't have the CDR. How does the armor pen work? If someone has 15 armor will I effectively be doing 25 extra AD damage with the Brutalizer versus BF Sword's 30 AD after armor?

If that's the case the Brutalizer sounds like the better deal because it's cheaper and it gives me CDR with only 5 less effective AD. It just bugs me that I will never build it into ghostblade when I can turn BF sword into Bloodthirster later on for more damage.

So what do you think? Brutalizer for CDR and armor pen/ad or BF Sword for more powerful AD and future upgrade potential? Or should I completely overhaul my Renekton build?

I usually start with boots and potions then finish my boots either armor or magic resist then I get a brutalizer. After those it usually something like warmogs>atmas>maw of malmortius>bloodthirster> then here i either get some more attack or a frozen mallet. This is just what I do and it works well.

u should get both. get the brutalizer first then build a phage. then get a hex drinker or the bf sword accordingly to what u need. sell the brutalizer end game and buy a last whisper.

Situational...if your against a tank like malphite or Cho or if opponent stacks armor then brutalizer. If not then BF sword.

IMO I think the Brutalizer is a much more better option early game then late. BF sword is something you don't need to worry about with Renekton so much. If you're super fed and can afford it then buy it but otherwise build a Brutalizer over BF sword.
This is my build with Renekton and it works. What you do is you get a Doran's blade then you build Brutalizer asap. Then you build CD/R boots, then you build a Phage, then Hexdrinker. Then you build Bloodthirster, frozen mallet, Maw of Malmortius, Ghost blade then sell the Doran's for a Guardian Angel. Works really well.

I am not sure why you never build the ghostblade on renec. early game it is an amazing item. it doesnt scale well into late game but you can always sell it for the last whisper later in the game if you desire.