I don't know how good the descrambling side of xaccel works, but the GPU transcoding of the streams is top!xaccel-codec is not best like astra. this software is totally shit, verry long scan sattelite transcoder, complicate select one stream and is verry buggy like streamer. Astra is totaly top like streamer. Xaccel-codec is sticky sandwitche with free-tools like opensource tools for dvb, ffmpeg and developer xaccel-codec create gui and that is all. i tested xaccelcodec and on firat transcoder from 0.8e have big problem with descrambling ts, but astra working ok. 500 euro is not big money for lifetime license from cesbo.
and transcoding use ffmpeg, is same like xaccelcodec