I am not familiar with the quality of the Vanguard ball heads, so I cannot speak to that.
However, for what it is worth, I like the ability to set a precise, quantifiable and repeatable minimum ball tension, instantly available, for each lens/camera combination I might mount, so that there is always some resistance to the camera just falling over when the main lock is released, no matter the weight combination. The Vanguard heads do not have that feature, even the largest, most expensive ones, that I can ascertain.
You have that dual feature with all the Sirui KX series ball heads, including the smallest K-10X. It shares the feature and the mechanism (a tension dialer within the locking knob) with the vastly more expensive Markins heads, and adds a highly useful feature the touted Markins heads do not appear to have - an additional dialing collar around the base of the locking knob, which allows numbered repeatability to the tension settings.
In use, you just set the range of tension so that your lightest lens/camera combination is zero on the dial, then memorize the numbered setting for each lens/camera setting up to your heaviest, and you are set. Just dial in the tension as needed for each combo, as needed. If you forget the number, you can just do it by feel, if necessary, then use it at that numbered setting for the rest of the session. I find this a tremendously useful feature I no longer would want to do without. See photo.
With the Sirui KX series (or, properly, my experience with the K-40X head) when minimum ball tension is set correctly for each lens/camera combo, you can place and use the ball head without fully tightening the locking knob. The proper resistance setting permits smoothly moving the camera when necessary, but keeps it firmly in place otherwise (this is very useful for leveling a K-5 using the viewscreen level feature). Or you can fully lock it down with just a quarter turn of the locking knob (and minimal effort) so that it will NOT move. Also, once you position the camera/lens under the proper minimum tension, it will not shift or move, even a minute fraction, when you tighten down to full, immovable locked tension. There is absolutely NO slop or fractional movement of the camera as you fully tighten the locking knob.
Another plus to the Sirui ball heads is the supplied instruction sheet. It is one of the best written, best illustrated manuals I can remember. It is clearly and carefully written in perfect, grammatically correct English, clearly and completely illustrated with excellent drawings and diagrams and very easy to understand. It is a model, in my opinion, for instruction manuals. And then there is the 6 year warranty.