If you live in the US, and your vehicle has a written warranty (which Suzuki does), then the warranty has to comply with the Magnuson-Moss Warranty Act; that means that the manufacturer can't stipulate that your bike has to be serviced by a specific shop or you'll void the warranty. Servicing your bike by yourself has no bearing on the warranty, and a warranty claim can't be denied simply because you do your own service.
The manufacturer under the Act can compel you to have any warranty work done at a service center they designate (which is why Yamaha can't do Suzuki warranty work, unless they're also an authorized Suzuki service center). If you do your own work, then keep your own records of what you do, along with things like receipts for stuff you buy. Those will back you up on any warranty claim. In addition to the receipts, this is the kind of written record I keep of my own maintenance:
The rules are different for guys outside the US, so the above only applies to riders in the States. I only bring this up because the warranty issue is kind of misunderstood, and the more unscrupulous dealers try and reinforce the fear in owners that, if they don't pay for their shop to do the work, the manufacturer will deny any warranty claim.
I appreciate what Bugzy is saying, but the idea that you're getting a highly trained Suzuki mechanic to do a 600 mile service when you go to a Suzuki shop isn't a given. As Lrobby99 already surmised, a 600 mile service is a glorified oil change. Now, it's possible you'll get a trained Suzuki mechanic if the shop isn't too busy with actual mechanical work, but it's just as likely your service is going to be done by the shop monkey who does all the low end tasks like oil changes, mounting tires, etc. That's usually because the highly trained guys are over working on the jobs that are making the shop a lot more money. Maybe he'll diligently check every fastener on the bike, maybe he'll diligently check every item under the 600 mile service that's listed in your owner's manual, and maybe he won't. And maybe he'll check the torque values of your oil drain bolt, and maybe he won't. Even being a trained Suzuki mechanic doesn't mean he's whipping out a torque wrench for that; lots of them aren't going to. There are plenty of horror stories on here of guys who took their bikes in to be serviced by "trained Suzuki mechanics".
I do agree that for some tasks, I'd be more comfortable with someone who's familiar with the ins and outs of my particular bike. There are always idiosyncrasies with a bike that someone familiar with the bike would be clued into. However, in the case of my bike, the local shop (now closed) had only sold one of them in the entire model history of the bike. Their Yamaha mechanics had no particular expertise with that model; when they inspected it, the guys in the shop walked over to look at it because they hadn't seen one up close. So, if they'd had to work on it, they'd have been doing what a non-Yamaha trained mechanic would have done; looked stuff up in a service manual. I bet a lot of Suzuki shop mechanics haven't seen a surplus of V-Stroms either, unless you go someplace like Romney Cycles. But a well trained motorcycle mechanic is a well trained motorcycle mechanic; they know how the general systems in a motorcycle are supposed to work, and for stuff they need specifics on, they go look in a manual. I'd probably trust an excellent mechanic whose skills I knew by reputation, but who might not be intimately familiar with my bike, over a mechanic of unknown caliber who happened to be employed by the shop who sells my brand of bike.