For all of you having difficulties with the post sagging a little bit and hearing a 'hissing' noise when the post goes bad, it is always going to be the same inner seals just about every time. It comes with the territory of hydraulic posts. It isn't super hard to service this post. For those of you that don't like dealing with the hassle of taking the post into the shop and having them send it to SRAM, you can fix it yourself and do it very cheaply. Also, I wouldn't bother with buying the 'super' rebuild kit other than 1 time. The majority of the stuff that comes in the large rebuild kit is worthless. It is a bunch of parts that will never go bad. Too bad the large rebuild kit doesn't come with a new top cap since that bushing will eventually go bad. The basic rebuild kit has all the o-rings that go bad the most and the charger bushing (the bushing you can easily replace).
I'm surprised at one of the posts here that said their bike shop couldn't service the post. That's pretty weak considering SRAM released the videos showing you how to service the internals on this post last year:
https://www.youtube.com/watch?v=XxgUK3gC_Fk
https://www.youtube.com/watch?v=w65kpbuxKP4
https://www.youtube.com/watch?v=rbHc4V6Ei14 - most important video
https://www.youtube.com/watch?v=KAmhSLir8hY
I have a 2 year old Reverb that I have probably serviced 6-7 times now. I weigh 240lbs geared up. This post has no problem holding up my weight. The o-rings are just going to go bad eventually, but they are easy to replace and very inexpensive. The basic service kit is only $8. If you don't want to buy that and go even cheaper, you can get all of the o-rings online. I use theoringstore.com, however, you eventually need to buy the basic service kit to get that charger bushing as that will eventually wear out.
Lastly, some folks talk about using 'upgraded' brass keys in their posts from TFT tuned. I'm sure they do a great job with their service, but wow, it is expensive! My guess is that they are just taking out some of the excess slop by using one of the larger diameter pins that are included in the large rebuild kit (another reason to eventually buy this just one time). For example, I have the 380mm, 30.9 post with 125mm extension. It uses the #3 brass key. That key is 2.65mm in diameter. The #4 is 2.67mm in diamter and the #5 is 2.70mm. Have too much side to side play? Just install one of the larger diameter keys. Done and done.
Oh, and if you want to get your own o-rings, I made a picture that I use so I know what to order (I measured all of these o-rings at one time or another). The ones in red are the most important and go out the quickest. The ones in blue I replace maybe once a year. If I didn't mark an o-ring that you see, it really isn't all that important. Just eventually replace it when it looks grungy.
<a href="http://www.flickr.com/photos/61714493@N03/11819965525/" title="Rockshox Reverb o-ring sizes by NHabes79, on Flickr"><img src="http://farm3.staticflickr.com/2826/11819965525_c26b9fb42e_b.jpg" width="738" height="715" alt="Rockshox Reverb o-ring sizes"></a>
Oh, and one more thing, make sure to put some blue locktite on the inner sealhead threads when reinstalling it or else it will come unscrewed. The o-ring will bulge out (as in the picture) and you will have the typical sagging/hissing issue.
<a href="http://www.flickr.com/photos/61714493@N03/9315045070/" title="Blown Reverb Seal by NHabes79, on Flickr"><img src="http://farm4.staticflickr.com/3806/9315045070_88afb36deb_b.jpg" width="1024" height="768" alt="Blown Reverb Seal"></a>