Hey Brian, I recently got the scrambler 30 as a day pack so I wouldn't have to carry around my larger pack.
I like the Scrambler 30, but there are a few things you should know about it before buying it.
First of all, this is a pack meant for climbing. The pack sits high up on your back, and the hip belt rides up higher than usual. The reason for this (I'm guessing) is because the hip belt is designed to be used while wearing a harness. The hip belt will likely be as high or higher than your belly button.
Because of this, the hip belt will pull the pack closer to your back instead of placing the pack's weight on your hips. This is great if you're hanging upside down on a rock climb or if you want to prevent the pack from "bouncing around" when moving quickly on the trail.
The plastic belt clips are a little wimpy. They haven't failed me yet, but I'm waiting for the day when I step on them. Keep in mind these can be easily and cheaply replaced.
The water bottle pouches on the side are not accessible while you're wearing the pack. Again, since this is a climbing pack, they have made the carabiner clips more accessible to reach climbing gear. Therefore, if you use water bottles you will have to take your pack off to access them. However, there is a pouch and opening for a hydration unit. I personally don't mind taking my pack off.
The backplate provides some good support and conforms to the shape of your back. I haven't removed it yet but I probably never will unless needed. Your back can and will get sweaty if you're exerting yourself, but that's how it is with most packs.
The shoulder straps are really comfortable, and wearing the pack (even with the high hip belt) is comfortable. The bag is made of really tough, durable feeling material too.
I loaded my pack down for a daytrip with several layers, a lunchbox, four water bottles, trekking poles, and several other accessories like sunglasses and gloves. Although my pack was stuffed, it was still really comfortable and I felt like I didn't even need to use the hip belt except when the pack bounced around during a rapid descent.
Overall, I found that it was a great day pack although its primary use is for climbing. It has a couple minor inconveniences like needing to take the pack off to access the water bottle pouches, but the pack does perform in terms of overall comfort and durability.
I never rock climb, but I still don't regret getting the scramber 30. If you have more questions about it let me know!