I gotta admit. My driveway is 300' long, poured in 2000 and has a couple minor cracks and gouges but has never been sealed. Of course, I don't put salt on it either. Salt is the enemy of concrete.
To have a consistent look, I'd suggest trying to match it. I'd try a Sherwin Williams or Benjamin Moore dealer if you have one near you. Box stores (Home Depot, Lowe's, etc.) won't have a clue. It looks to be solvent based.
Looks like an acrylic or arcylic-urethane with stain pigment incorporated into it. Some of them are good with intercoat adhesion. You'll probably need to do some testing in an inconspicuous area...It looks film forming rather than penetrating.
Yes they've made a lot of advances since the original 3 part formula. I stopped using Ballistix due to all the bad raps they got in the epoxy flooring forums on social media. I don't do a lot of garage floors, mostly commercial projects so it's just sometimes that I can use that type product...
I put it down in my laundry room a little over a year ago. It has held up well, however my laundry room does not get severe traffic. Just our feet and laundry baskets. The 3 part mixing instructions were insane.
With epoxy floors, cheap is usually NOT the way to go. $4000 is a touch high, but not unrealistic. It all depends on how much work has to be done on the damaged area and the quality of materials used. I'd be around 3.5K if the repair work was minimal. 2 day process.
Presuming contractor B has a good reputation, methinks you're ok with the same product -after all didn't the first guys show you a couple projects that did not stink? While Rhino Linings is not my coating of choice, Rhino is certainly a reputable company. I don't like the approach contractor A...
200 grit sanding on a coating may be just fine for applying a refresher coat -provided it's well bonded. 200 grit on bare concrete will not do the job, you need much much more aggresive abrasion.
Asking which 100% solids epoxy is best is akin to asking which car is best. Everyone claims there's is the best. In actuality, there are a limited number of actual manufacturers of epoxy. The vast majority sold is private labeled product from one of these manufacturers. There are a lot of...
My experience with Stonhard is hit and miss. Sometimes you get a good crew & a great job, sometimes it looks like dog poo when they're done. It all depends on the crew you get, their products are good.