If you think the 802d is physically unstable - have you tried to shift one?
Methinks surely not.
I had a set of three 802d2s across the front a few years ago and when I sold them I struggled with the ability to move them!
I cannot envisage any normal circumstance where their stability can be questioned.
After a spell away with Proac Carbon 8s I am about to take delivery of 2 800d3s in the next 10 days.
They are on castors so are moveable yet very solid/stable and do not look too much larger than the 802d3s. A point here is that the new d3s are hugely popular, and for very good reason indeed. I originally compared the 802d3 with the Kef Blade and for me it was no contest. It seems that the 802d3 owners are so pleased with the product they are switching to the 800d3 at just a cost uplift, as I have done. There are a number of reasons for this, so if you are talking about the d3s then it must be the 800 instead of the 802.
If the older d1 or d2 then the margin is somewhat less.