I've never really considered myself a collector of games. I'm not sure where you make the distinction between someone who is and isn't because I'm also not someone who trades or sells games. The main reason for that is because as I've found in the past you always regret because you always want to play that one title you don't have.
So reading the article about collectors on GI.biz struck a chord with me because it's something I find myself pondering now and then. Like most people, I use and various download services mainly for convenience or because they are the only way a certain title is available. Most of the time I don't have an issue with this, but there are a few things that do tend to bother me. The biggest issue obviously is no having that actual physical copy that of something. Maybe I'm old school, but I like to have something to show for my money, especially when it costs as much as some games do.
The other issue to me is titles costing the same amount as a retail or physical copy. It's not that a digital download necessarily has less value to me than a physical one, but why am I paying the same amount for just data, which I then have to download, spending more time and download quota on. I live in Australia, we don't have internet at an ungodly speed, or uncapped downloads, so yes, if for any reason I need to reacquire certain titles it's a hassle. Yes, you can back them up sometimes but that's another issue.
Something else I've thought about is the downloadable content available for titles that seems to be released these days. Mostly things like expansions, because they are larger and more expensive. What's going to happen when something like the Xbox360 is a retro console and you want to play a game with a specific expansion, but for whatever reason you no longer have that expansion installed. On a PC this isn't an issue, those kinds of things are always available somewhere. But are Microsoft going to offer this content that you've purchased on Live forever? I'm sure there is something in their TOS regarding this, but still, you may have paid money for something you can no longer access.
Which all leads back to the start of what I was saying. You are essentially paying the same price for an item, which acts like an unlimited rental. If the distributor decides to cancel their service at any given point, you most likely won't have further access. Though regardless of price, this would still be an issue. I think for the moment, I'd much rather have the disc on my shelf, knowing I can access whenever I like.