Isolation platforms

It would be for looks unless you used appropriate feet to isolate the platforms. Adding the wood may also introduce a subtle tonal change to the system. You could try adding isolation feet to the amps without the platforms. 

@noromance Ty for your response. I wanted to use the 3 in. amp platform because they were sitting on just my tongue and groove wood floor. I was also thinking the same thing that if I bought the other 2 platforms for my preamp and CDP that it would more for the looks more than isolation. The 3 in solid maple platforms do look nice though. Lol. 

IsoAcoustic platforms, feet, etc are a nice upgrade in my opinion. Unlike wires and cable where many say they hear no difference [myself included] I find that isolation does work on anything which causes vibration. I draw the line at amps though. 

Sounds like someone needs better sources and amplification. 🙄

Unlike wires and cable where many say they hear no difference [myself included] 

First, did you hear a sonic improvement with the amp stands and audio rack?

If you want to improve the sound of your components then I would look to Townsend isolation devices and even more, Silent Running Audio platforms. These will contribute to the sound quality far beyond wood racks or shelves. I believe the best use of funds is a good rack (without integral isolations devices in it like your racks) and isolation devices under the components. Isolation devices are likely to have the biggest impact on turntables, tube amps, tubed DACs / CD players, then tubed phono stages, preamps , other tubed components and then all solid state components… in roughly the same order.