I have the "travel light" which I like because it's a different color than everyone else's (and thus easy to find) but doesn't have a ton of storage, so I always have to carry separate mute and music bags. Also, the backpack straps (you have to purchase them separately) are sort of upside down from the rubberized feet that allow you to set the case on end. It's a bit weird, but not weird enough for me to send the thing back, so I've just been adjusting.

The "contoured" version has a bit more storage (though I think still not big enough for mutes, but definitely can handle oils) and can also accept backpack straps. If I had to buy it again, this is probably the one I'd get.

The "standard" version has enough storage for mutes inside the case, but I'm fairly sure you can't put backpack straps on it (from the image on Amazon, it doesn't look like it has the correct loops available), and backpack straps are somewhat necessary for me.

I haven't seen the platinum series in persion, but I'd be hesitant to use it based on it's images...looks like a semi-soft case (it advertises wood panels at the "back" and bell only, instead of all the way around). I have enough hustle and bustle in my life that I wouldn't feel secure that the case wouldn't get tossed around. IT's probably lighter than the other choices, but doesn't work in my life. That said, the permanently attached backpack straps look better than the detachable ones that go with the other cases.