Before I give you any information, download the demo's first, mess around with them for a month, then make your choice...
-Edit: not sure if there is a photolab demo.
Visionlab is a HUGE improvement in your filmaking. Both Effectslab Pro and Compositelab Pro are excellent editors, and Visionlab takes you a leap further. It mainly depends on what you need for your filmaking. What do you need?
Few things about Visionlab:
-Visionlab has the electricity engine. I have grown fond of it. (not many electric presets to start off with, not too many to download... YET)
-Visionlab has extended both of Effectslab's and Compositelab's features. HUGE EXTENSION ON GRADING.
If it were me, I would invest in Visionlab. But this is totally up to you, don't make your decision based on this.
While I don't think you actually need it, it offers more features then both Elab and Clab, but it is mostly an extension of the two. If you already have both, I don't think you will seriously need it. -just my opinion. But if you are a serious movie maker, and really find use of this, I would say go for it. BUT DOWNLOAD THE DEMO FIRST!
I can tell you Visionlab is a lot of fun, even though I don't actually own it... YET, I have played around in the demo for a long time, (which is basically the full version w/o presets)
Go with what you want! Have fun...
-heads up Fxhome... I am in the midst of creating an action/drama movie. It should be done by this summer... I will post a storyboard soon, just to see how everybody reacts!