I'm partial to Bobcat, but there have been a few issues with people that have bought late model tracked machines and had the travel motors fail causing massive damage. Hopefully, it is only the tracked units, but you never know.... I'd like to see what other members have to say on these two machines.
They are the most popular over here, all i have ever worked on. Back when i started messing with them their service department was all too happy to talk to me with issues i was having. Not sure how they are now though. Parts availability is excellent, i had a machine that was 30 years old, pretty much every part was still available. They have parts for even older machines still, prices are not awesome but you can get them. The major parts are not all dealer only, they don't build their own engines, so you have choices unlike NH, they have their own engines that cost both arms and legs if one is to go out on you.
I would opt for the CAT any day. I am partial to them. I work for a CAT dealer and we see VERY FEW failures of the 226. They have been most reliable. Plus no exhaust after treatment.
Here are the numbers on both, side by side: http://www.specguideonline.com/compare/bobcat-s510/caterpillar-226d Bobcat will lift a bit more, but Cat has more power. Looks like S510 has the Doosan engine, not Kubota. The Cat will be Perkins-powered, although badged as a Cat. Interesting decision. Are you planning to keep this machine for a while or trade for new at regular intervals? Parts availability and cost could be a deciding factor. There are dealers for both in my area too. My Bobcat dealer has to be one of the better ones in the area, and goes out of their way to give great customer service. Don't know about the Cat dealer. HTH - SR
The CAT has a 2.2 turbo and has been a very reliable machine. Typically, the CAT will hold its resale value better and being a B3 instead of a D model, you won't have to worry about Tier IV final with regen and dpf filters. I'm all about simple.