Just a quick observation.
There were 2 noticable hits in the current chapter that BB landed. They were:
1. Right punch - His 1st attack. He grabbed Ace first and then punched him in the gut/stomach, sending him back.
2. Chop on the neck - This was his next attack after Ace used that double spear thingy on his chest.
I just noticed that there was no panel depicting BB grabbing Ace prior to chopping him on the neck.
This leads me to believe the following:
-BB is "being his element" all the time. His "DF negation powers" are automatically turned on ALL THE TIME (following what I have noticed), but his "Black Hole Vortex" power is another thing that needs to be invoked/activated.
-All he needs to do is for some unsuspecting logia users to allow him to come near first and land a hit since he does not really need to grab the opponent first in order to hit them.
-If in case there are smart logias who would want to play keep-away, the "Black Hole Vortex" ability comes in and forces them to fight BB in close-range.
-BB said in the translation that there are some things he can suck up. He did not specifically say what, but I interpreted it as "Well, I can suck up stuff, but not all of it." This leads me to believe that there are certain "rules" for his Vortex Ability which would probably be, (based from observation), he can suck up inanimate objects but not living objects. I am not 100% sure of this theory, but the wierd thing is, if he can suck up human beings in his Vortex, why didn't he just suck Ace up in that Black Pillar? If we remember correctly, when he activated the Vortex ability, he propelled Ace to him and opted to grab him instead of just sucking him up.
-Fire is not a living thing, so, it can be sucked up. However, like I said, BB needs to activate the Vortex ability first before he can suck stuff up. Some people already explained that the reason why he got hit by the Fire Lance and the Fire Firefly attacks were because he was unprepared. I believe this. He shrugged off the Fire Cross attack after eating Ace's Lance and after Van Auger's dialogue, it was shown that BB was not having a hard time with Ace at all. (Which makes me wonder what the hell is the point of Ace in using the big-ass Fire Ball attack in the 1st place - Maybe it's just Oda wanting to show us what Ace's most powerful attack is before he loses/gets killed off)
Now, given the above scenario…if indeed BB can't suck up human beings in his Vortex, then Luffy still has a shot against him. If you notice the pattern that Luffy has been "developing", he's just utilizing his rubber abilities to augment his range (most of the time) and apply more force/speed to his attacks. HIs strength has always been there. True, the rubber abilities add so much to his strength, but minus the Gomu-Gomu fruit, I believe he can still fight against some strong opponents. His latest fight against the CP9 showed him (and us as well) that he has a lot to learn in terms of being a physical fighter because he depended so much on his DF ability just to emulate the Rokushiki techniques.
Now I finally see boiga's point. If it is indeed true that BB can't suck up human beings, then Black Hole Vortex + Luffy accelerating to BB with a Gear 2 Bazooka = pain for BB. BB negating Luffy's rubber properties would mean jack shit since Luffy has range on his side and his attacks will be amplified by the acceleration BB produces. Therefore, Luffy is still THE perfect match against BB. (As well as prolly CP9 zoans).
Well of course, all of this theorizing goes to shit if BB can indeed suck up human beings, but it's worth a shot, IMO.