With the exception of the torso area, this jersey is a lot like the Zulu jersey while retaining the more moderate price of 50$. It's a comfortable and pretty baggy jersey with no points which feel like they need to be adjusted when it's first put on. The material composition of the jersey is 40% polyester, 60% cotton, and it is indeed the same milspec rip-stop material which can be found on the rest of Valken's pants and jersey's. It's a pretty hardcore material and is a little rough on the skin, not so noticeable on the arms and legs but on the torso it's abrasive qualities will be especially noticeable for the first few game days. Like the other Valken products, a wash or two will take a lot of the rigidity and roughness out of the material but until then I have to recommend: do something to save your nipples or they'll be rubbed quite raw! It's fairly cool to wear, especially if you use a harness but some heat issues may become apparent when a vest is placed over top of the Sierra jersey.
One area of slight discomfort on the jersey which isn't so easily overcome is the velcro running up and down the sides of the torso. The velcro here can be a little annoying against bare skin and it has a tendency to scratch a bit. An undershirt can be worn to alleviate this but this will result in some more heat retention. Scratchiness aside, these velcro strips serve two purposes, first is allowing the user to conceal the front of a pod pack underneath the jersey and get leave the camo scheme of the top unbroken by a thick belt running through the middle of it. Their second use is allowing the user to adjust for ventilation. The strips do run straight down the jersey when first taken out of their bag, but they can be offset at an angle to let a little air make it's way to the the user's core. Another way to get a little more air circulation is to purchase a jersey one size larger than necessary. The extra loose material will help gain some bounces and not cause the material to stay tight to the user's body letting air circulate better. Though the jersey is touted as having “breathable milspec material,” most of the ventilation the user will get from this jersey is going to come from air entering around the waist and any looseness around the V-neck. The material itself is good at insulating in this case and does a better job of cutting the wind than letting it pass directly through to the user's core.
One area of slight discomfort on the jersey which isn't so easily overcome is the velcro running up and down the sides of the torso. The velcro here can be a little annoying against bare skin and it has a tendency to scratch a bit. An undershirt can be worn to alleviate this but this will result in some more heat retention. Scratchiness aside, these velcro strips serve two purposes, first is allowing the user to conceal the front of a pod pack underneath the jersey and get leave the camo scheme of the top unbroken by a thick belt running through the middle of it. Their second use is allowing the user to adjust for ventilation. The strips do run straight down the jersey when first taken out of their bag, but they can be offset at an angle to let a little air make it's way to the the user's core. Another way to get a little more air circulation is to purchase a jersey one size larger than necessary. The extra loose material will help gain some bounces and not cause the material to stay tight to the user's body letting air circulate better. Though the jersey is touted as having “breathable milspec material,” most of the ventilation the user will get from this jersey is going to come from air entering around the waist and any looseness around the V-neck. The material itself is good at insulating in this case and does a better job of cutting the wind than letting it pass directly through to the user's core.
Some similarities this jersey has to the Zulu model: the areas of the arms where a gentleman can place some patches are in the same spot and of the same size and the Sierra jersey also possesses the clear plastic enclosure for a event or season's pass. The arms have the same elastic cuffs at the wrist as on the Zulu and the elbow pads are of roughly the same size as those which are found on the more expensive model. So whats one thing which the Sierra jersey can claim which the Zulu one can't? The Sierra jersey won't generate piles of fuzzy excess material as a result of a little friction from the wearer's vest. To some, the fraying and fuzzing of the Zulu model is a non issue but to my crew, this is the biggest gripe of the whole. I can't give the Sierra jersey too many bragging points here though since when it comes right down to it, the Zulu model will keep the user a lot cooler.
In regards to lifespan and overall quality of this jersey, you aren't missing out on anything when you buy it. It's definitely made of some tough stuff and there have been zero rips or broken threads on the Sierra jersey belonging to one of my team's most aggressive players.
As per usual, Valken's Page (link) has more pictures of this jersey and the specific features.