Great for Mountain Biking & Hiking
Just returned from using this pack in Colorado for two weeks of Mountain Biking and Hiking. I found this pack to be excellent with ample pockets and little places to store bars, camera, jackets, lunch etc. I loved the blue color also. I have owned many packs from various manufacturers and I have to say this one is tops. Magnetic holder for the bite valve is genius. Smaller pockets on the waist strap are great for your camera and and emergency jacket (North Face Verto). You can stuff it if you need to, very durable and I found it to be very comfortable with lots of adjustments available for custom fit. I stuffed it and never had any shoulder fatigue at all. Very comfortable !!! Highly recommend !!!

Mantra 30 vs Raptor 6
I really like my Raptor 6 hydration pack - light, cool, compact and comfortable - but very little storage space for longer hikes. I bought the Mantra 30 in preparation for a hike to Yosemite later this summer. I'm a 100 lb, 5'-0" tall woman and the Raptor 6 S/M works well for my frame. I also bought the Mantra 30 in the S/M and it feels like the same size frame - but when you load it up, it does change your balance. I did a test run today with 10 lb (including pack, water, a few groceries) and walked a short 20 minute uphill road. I had to rush to pack it - and these packs are not meant for bulky items since the frame squeezes everything flat - so it was a bit unbalanced. I'll do another test to see how it feels properly packed and weight distributed. Mantra 30 has a lot more storage compartments than the Raptor 6, but it's still pretty minimal packing space - so I'm glad I got the 30 instead of the 25. The waist hip storage is set too far back - though I think I can make it work for camera storage and chapstick. The only issue I've had with both Ospreys is the Nalgene water reservoir. BOTH my Raptor and Mantra have reservoirs have a funny plastic taste that I never had with my Camelback system that I got for an Osprey Aura pack. I've tried baking soda in addition to regular soap and I can't get rid of the taste. Anyways, I still like the pack - attaching a photo to compare size between Raptor 6 and Mantra 30.

Great pack for hiking
My husband and I both purchased the Manta 30 about 6 months ago. Since then we have used it on multiple hikes, including two 14ers. You are able to carry enough supplies, layers of clothing and water to hike a 14er without problems. I will say that my s/m size pack carries noticeably less than my husbands m/l. There are pockets on the side that are perfect for carrying a bottle of extra water on either side. The water reservoir is stable and you don't feel water sloshing around when you are scrambling. As other reviewers have mentioned, the pockets on the belt are not functional. They are too far back to be easily accessible, but that is my only complaint about the pack.

The daypack has evolved!
I bought the Manta 25 and now wished I had the larger one. This backpack is excellent for both hiking and cycling. The newly designed hydration bladder (with wide mouth and handle) is flat on one side to fit the back better, and the belt is actually functional, unlike most hydration pack belts. The magnet to hold the bite valve was a genius idea, along with the bite valve swivel so that it can be protected from hitting the ground when you take the backpack off. The pack has lifter straps so that you can make it fit closer to the back as the water is consumed. The only "con" would be that the hip pouches could fit farther forward to make them more accessible. The "pros" so outweigh that one "con" and make this the best daypack/hydration pack on the market!

Another fantastic Osprey pack!
Bought this Osprey Manta 30 in the small/medium (I have a 32" waist). It fits great. This bag is awesome and Ive used it to go hiking a couple times already. You can't go wrong with this daypack. It will hold anything you can throw at it! Infinitely adjustable, The included Hydraulics Fluid Bladder is the best in the business and the included Rainfly is a nice and useful addition. Shipping was good and very happy with the product. Osprey's warranty is absolutely the best!