I did a hard break-in, changed the oil at about 100 miles, and did the second oil change at 600 miles. I have 1700 miles on the bike now. The only time I've taken a bike to the dealer ever is for recalls, warranty work, and for a free 600-mile service that came with a Triumph. Yes, if it had any problems, I would take it back, but probably before 600 miles.
The question comes up about warranty and having your manual stamped for warranty if something goes wrong. I suppose that could come up. Say you change your own oil, the drain bolt falls out, the oil drains out and your engine seizes. If you had your manual stamped, that wouldn't be your problem. If you had done the work yourself, they would probably question whether you tightened the drain bolt properly and may not pay for a new engine. (Generally what would happen is the oil light would come on, the bike would run rough, you would stop, figure out what happened when you see the oil under the bike, buy a new bolt and put some more oil in and everything would be fine)....but you could damage the engine. So there probably is some peace of mind having the dealer do the maintenance. I just take my chances and it's worked out fine and saved me a lot of money over the years doing my own maintenance. An oil/filter change costs me $25 max.