Well, more like initial thoughts for now. I'm sure given the nature of this vest that some members here would be interested in it, but there isn't much info available at all since it just hit stores. For those unfamiliar with the SJ vest, here's a link for more info:
My first impressions...
Fit and finish:
This vest is very well made. While only time will tell, the materials and stitching feel like they will hold up over time. The mesh breathes really well and the soft trim seems to be about as chafe free as is possible. Much better than the Osprey and Camelbak packs I have tried in the past.
On the scales, the vest itself weights 8oz (LG) and each bottle is 2.75oz for a combined weight of 13.5oz with both bottles.
I have a 40" chest and UD says a size large is for 36" - 44" chest. That said, while I haven't tried on a medium, I couldn't imagine the large being too good for any smaller of a chest. Loaded to max and tightened all the way it is just right on me. With a t-shirt on, there is just enough space to fit one hand underneath with my chest fully expanded. Of course, fit is purely subjective though, but if you're in the 36" - 39" range I would recommend trying both the medium and the large to see which works best for you.
This thing can fit a TON! I couldn't believe how much I could fit in this and how versatile the storage options are. All compartments, with the exception of the very back main compartments, are very easily accessible with the vest on, from the side pouches to a jacket in the rear bungees. The hydration bladder area in the main compartment would not accommodate either a Camelbak or Osprey 3L bladder as it is too short. A 2L should fit fine, but I don't own one to confirm this. I stuck a .9L Evernew un-bottle in instead and it was a great match. Due to the profile of these, I'm sure I could fit two of these full in the back should I be going to an area with limited water resources, which would give about 3L total with the 2 UD bottles. There are small pockets everywhere to stash gels, bars, or whatever snacks/supplement you may want to take with you.
This is my "off" day, but I had to try it out. Loaded it up with 3 full bottles, jacket, gels, phone, wind pants, spare layer, etc. The vest felt very well balanced. There was very little bounce. As I mentioned with the sizing though, if I were any smaller, it feels like it would shift a little.
So these are just my quick initial impressions. For now, the only nitpick I have is with the cell phone pockets. It is a little on the small side. I have an iPhone 4s that I have in an Otterbox Defender case. It will not fit in the pocket with the case. The opening is a little bigger than the phone itself without a case. The primary issue though is with the depth. To secure the pocket with the velcro closure, my phone really needs to be stuffed down in. Since the pocket mesh is elastic, should that velcro come undone, there is definite concern about the phone getting ejected while running or when taking off the vest. I will just have to keep a close eye on this in the future. Anyway, these are just my initial thoughts for now and I will update this after I get to take it out for a "real" run in the mountains next Monday.