I realize this questions is a bit old, but these are the kinds of things I read when searching for windows, and hopefully I can help a future window shopper. We are in the middle of a terrible experience with Inline.
We purchased 27 double hung triple pane replacement windows in October of 2011, Eternity 9000 series, Synergy glass package I believe. Since the day of delivery, the window locks have been literally falling out of the fiberglass. We have come to find out that the screws were just screwed in to the fiberglass without a "backer plate" to hold them there, so they are tearing out. This is a design flaw and not something that can be fixed after the fact. In the three months since delivery one inline tech came on site to see our issues and basically glued a few lock in with silicon, which just today popped back out when we tried to show them to another tech. Today, two months after installation was completed (they told us to continue with installation while they "fixed" the problem), a new tech finally came out. This poor guy knew nothing of the back story and was also going to try using silicon to "fix" the locks, until we showed him the last attempted fix. This is seriously a design issue and is a problem with every single one of the 27 windows; Inline has so far been unresponsive to the company we bought the windows from. We spent a large chunk of money purchasing and having these windows installed, and they are pretty much garbage. We are considering legal action.