I am thinking about doing this with my cacti collection .
what do you all think about it ? if anyone has experience with this way of planting pleas chime in.....

Looks far too neat for my taste, to be frank.

Looks great to me!..and Jeff if this method/layout appeals to your desire of how you would want to present your collection, I say go for it!!
And this opinion is from somebody who does this with her plants at home:

Looks interesting! But I won't show you how my plants look!! Hetty I'm with you I like the wild look too!

Is the space you intend to use covered? I lost plants to the monsoon rains last summer. 'Good dirt' can only do so much in the presence of constant rain, missing sun. If I tried this, dogs would run through it and ruin it immediately, stray cats would, well, you know. I can't probably imagine everything my son would think of doing, but... yeah. Aside from logistic (and 'pest') issues, if you like this look, you should absolutely do it! I like to get more close'n'personal with plants than it looks like this would allow. Can you walk around in the gray gravel? It looks like it would shift, and being as (NOT!) graceful as I am, I would fall onto those prickly plants!

If I were going to sink the pots in gravel to create a naturalesque look, I would cover the edges of the pots with extra gravel.

It looks nice, but I have seen some of my columnar cacti get mushy quite quickly when the container is too deep and wide, so I end up chopping them off to save the plant. I would use more compact containers, their roots are shallow anyways. It is good to see the plants are elevated on gravel, so water won't puddle.

Now if that area gets sunny and is totally protected from much rain I'd say it is really pretty

Somehow it doesn't look ok to ME! But... every gardener looks at their piece of heaven with their own eyes. So indeed, if this is the look you are going for, go for it