I just finished a 10-day solo trip on the Green River (Labyrinth Canyon) and the Viper was amazing. I've been paddling the Viper since May...mostly lake and one three-day river trip. I haven't experienced any of the elbow fatigue I suffered last summer. It is a beautiful paddle, too. The large blade also can move some water!
Can't recommend the Viper enough and the folks at BB and ACK were great.
After much research and query I decided on the Bending Branches Viper which I purchased through Austin Kayak with a nice promo code/coupon from previous purchases through them.
Sizing worried me a bit but the folks at both Bending Branches and Austin Kayak were really friendly and helpful. I decided on the 50" after a long chat with Austin Kayak about sizing, canoe width (Penobscot 16RX) and torso length.
The paddle is light and enters the water beautifully. The longer and wider blade moves some water - something I really like on the lake...especially when the winds pick up (I mostly paddle Lake Dillon at 9,000' and the winds can get kind of intense).
If you're looking for a really nice double bend paddle with a beautiful face... get the Viper!
I ran this solo on the Colorado in May (Ruby/Horsethief section). Fast flowing water and high volume (volume nearly doubled in one day!). Can't imagine a better boat to do this in! Expedition capable all the way. Had it loaded with gear and it was super stable, very responsive (after a couple of gear position/weight tweaks).
Handled Class II extremely well!
I also put this canoe on the lake, both tandem and solo. Again, stable and responsive! If you're doing any advanced level of canoeing - especially multi-day River, this IS the canoe.
Thanks Old Town!