I purchased my Spyder E-99 Avant with the intentions of it being anything but stock and at the time of writing this review only the body and the grip are stock. I spent a lot of time on the web researching this particular part.
There are a lot of articles on the kick of the spyder and after taking the time to run mine through its paces on all stock components and what I know about firearms I came to the conclusion that the majority of the markers kick is coming from the moving parts.
I read all the reviews, tech articles (which by the way are great and my thanks to the PB community for them) and the individual manufacturer's specs on the different strikers out there and narrowed it down to IPS and ACP; at the time of purchasing this striker ACP was and still is working on their 2nd generation striker; so I decided to purchase IPS Nightstriker XL.
To begin IPS is great I had several correspondences with them and they were very helpful I can not say more about their service. When the striker arrived I was completely amazed at the weight reduction over the stock striker not to mention the workmanship that went into the product. Stock striker coming in at about 62.5 grams or 2.25 oz and the IPS Nightstriker XL coming in at 24 grams. Now with all the upgrades in place I gassed up the marker and took it out back. I, right off the bat, noticed a significant reduction in the kick/recoil of the marker and found it very easy to keep my barrel down and on target but like most blow backs there is a flux in shot pattern.
Next and always a favorite among the critics of the Spyder is noise; now I don't have the ears of dog but I got a strong impression the overall repor of the marker was quite a bit lower. Having this in mind I broke out my 2002 Vertical Autococker; which is far from stock too, and began to test the noise between the two markers. I did not actually take a decibel reader out, since I don't have one, but I would gather to say both markers repor sounded very close. The only distinction coming with the back block of the AC.
After several cases of paint the NightStriker XL is holding up nicely and figure it will last a long time.
Great product and do recomend it for any Spyder owner out there wishing to upgrade this part.