Are you dealing with the owner in both cases? With a couple of exceptions in the area, I would always rent from an owner over a management company. If you are dealing with the owner, chances are that they are much more involved in the running of their home. If you are dealing with a large ManCo, you may be dealing with someone who has no vested interest in the home at all. "Its just a job". It doesn't alwasy hold true, and there are some management companies that are great.
I can only speak from my experience with Global. On behalf of another owner, I have checked in on a home that was managed by Global. Long story, but put it this way. Based on what I saw/experienced, I would not use Global as my management company. Some renters will have had a great experience with them. When I did the home check, I went in with a critical eye - as though the home were my own, with my picky standards and how would I feel about renting that place out. I would not have been happy with what I saw. It wasn't a disaster, but there were several issues that I would have been totally unhappy with.
No management company / home will be perfect - this will and do go wrong, even with the best of owners, even with the best of management companies. It is how things are put right that is the issue.
Also, with the different homes, make sure you are comparing apples to apples. All homes are different, and there are things that may make the price worth more to you for example, quality of furniture, extra amenities such as internet, computer, games machines), location (close to clubhouse, overlooking pond / conservation etc), larger size, more bathrooms. It is easy to overlook these when you have been looking for a while (it can all become a big blur!).
Hope this helps,
-Kay