I've been playing Vlad recently and I'm still debating a bit on his build.
I almost ALWAYS goes for Sorc over Luc. You heal based on the damage dealt, enemy gets MR you will fall off fast or need to rush guise/void.
Visage is entirely situational, I almost always get it mid lane but if they only have one threatening AP, then don't. The heal benefit/CDR is good but it delays better items. You might as well just get Abyssal since Vlad's range is low and he's always in range for the debuff.
If mid, I usually go boots + pots, rush revolver, get a NRR or GB depending on how well I'm doing in lane or outright buy a visage if there are two APs on the other team and I'm taking some harass in lane.
From there, Zhonya's if they can burst me down easy, Rabs if I'm feeling cocky, WOTA if we're double AP. Guise if I didn't get Visage and they have some MR. Abyssal if I didn't get Visage.
Late gate you should have SORC-WOTA-RABS-ZHONYAS-ABYSSAL(or void if someone else got it)-Rylai.
Rylai is situational but sometimes you really need it.
Vlad gets countered hardest by -
TOP: Warwick, Riven, Yorick, gap closers with early game power
MID: Swain, Fiddlesticks, Fizz, Mordekaiser, Malzahar, Ryze
I wouldn't get Abyssal early vs voli. Doesn't do much for you.
Don't pick Vlad top against exceptional gap closers, you will get raped early game. You want him against someone that can't outpace Q spam. Vlad does well mid against a lot of the usual AP champs but has some bad match ups, top lane he loses to a lot of the new bruisers early.