I never went to any Symposium Plate and looked for something serious instead.
VP is made for microscopes. I own a few and they are reliable from Day one.
But there is one detail to think about, NEVER move the VP when the feet are filled. All air loss is based on that mistake. But this is noticed in the manual.
When they are new and filled first, the air hoses will be stretched a little bit, so refill has to be done about 2 or 3 times after 2 weeks, when the hoses have their final diameter all is stable. For mine I refill them probably all 4 months.
Car Tires for example need a check too, based on diffusion.
The VP can also ordered in active version (compressor).