Stonescapes is from a company called NPT. "Stonescapes" includes both standard and mini pebble as versions of Stonescapes.
http://www.nptpool.com/pool-finishes/stonescapes
PebbleTec is also a company. Their standard size pebble finish is called "PebbleTec and their smaller pebble version is called "PebbleSheen" which is their mini pebble version
http://www.pebbletec.com/products
DiamondBrite is from SGM
http://www.sgm.cc/html_Pool/HomeOwners/gallery_diamond_brite.html
There is also a company called Wetedge that offers several different finishes as well.
http://www.wetedgetechnologies.com/component/productlisting/?Itemid=294
Cost for finish types vary by region. What you may pay for a finish in a Chicago suburb may be more than me being in Southern California where there are many more gunite pools per capita here and most likely more installers.
Regarding Diamond Brite vs PebbleTec there are many opinions on this subject. Comes down to the look your going for and how much you want to spend for durability. Basically Diamond Brite, like plaster, use an exposed aggregate + cement for its makeup. Difference is that plaster uses marble for its exposed aggregate where Diamond Brite uses quartz for its exposed aggregate. Quartz is much harder than marble so it's more durable.
http://www.thediamondbladedepot.com/shop/images/Mohs_Hardness_Scale.gif
PebbleTec uses river rock for its exposed aggregate. Durability is highest with pebble products since more of the aggregate is exposed to the water compared to the other finishes like plaster and quartz based finishes which have more of its cement exposed to the water. This is also the reason why you will see more mottling with colored plaster and quartz finishes compared to pebble finishes. The pigment is in the cement and the water chemistry will fade it in places and there are no pebbles to hide the mottling. But plaster and quartz finishes are smoother than basic pebble finishes so you may like that. Then there are cement modifier finishes like Pebble Fina but rather then to get into that I'll stop... this is all tip of the iceberg regarding finishes and doesn't really address your questions. I went though all this a few months ago with my own research for my build and I still don't think I learned 20% of what's out there on this. (by the way anyone reading this find errors feel free to correct it- this info was mostly from my builder and internet research)
There are only a hand full of installers qualified to install PebbleTec in any given area so you'll find it's more exclusive than other pebble finishes and thus quality of install is controlled better but then the price is usually higher as well. Diamond Brite is a pre-mixed quartz product that any plaster installer can procure but that doesn't necessarily mean it won't be installed correctly. I guess you need to check up on each company and see their past work. Do they have a picture book you can look at? Maybe ask for references and check them to see if the people have any regrets about the finishes and/or installer.
Don't quote me on this as it might vary from installer to installer but I believe the warranty on Diamond Brite is 10 years where is PebbleTec is 20 years. So if I had to choose between two finishes: a quartz finish and the pebble finish was only $500 more then the pebble finish is what I would pick.
You mentioned possibly just re plastering and if you go that route I would recommend staying with plain white. It will be the least cost finish available and you won't have to worry about pigment mottling. Warranty is usually only 5 years or less for plaster but you'll find there are many people here who go triple, quadruple that time without issues if properly maintained.
Buffing 10 year old plaster? Never heard of buffing plaster but 10 years and having problems sounds like you got much of the life it had in it, who knows how thick it is even if you chose to buff it would it be ok assuming it's not buffed down to the gunite?.
