I'm not sure exactly what specifically you want feedback on, but I watched some of the videos so I might as well say what I think.
You're new guitarist seems fine, competent at what he is doing.
Overall, I think your band can do with a second guitarist, there is just too little going on while the guitarist is soloing, and given the basic structure of your songs, the music can really do with the depth of a rhythm guitar. If you are planning to focus more on recording than live gigs then this might not be a problem, but I used to play in a Doom/Death band with 1 guitarist and although we were pretty loud and heavy we suffered greatly due to the lack of atmosphere when the lead ran on its own.
Coming to the music and song writing, there really isn't too much new or exciting about the riffs. It can get tired really quickly without an edge, and all of this has been done better before by bands like Kyuss and Danzig. I'm not saying it's all bad, Cloud of Souls was pretty mesmerizing at times, nice melodies. Enter Oblivion had an interesting intro, very much reminding me of Danzig, and some parts later remind me of latter day Darkthrone, almost blackened doom riffs. Lots of punk influence in the riff structures, but not a lot going on to back up that aggression.
The dynamic needs to be worked on, the drummer really needs to try and experiment more, since he is pretty loud in the mix, and can really take attention away from the riffs with his monotonous style. The vocalist needs to grow into his voice, the rasping vocals are pretty cool, in fact although I normally enjoy doom with singing vocals more I think the rasping vocals suite the music better. The singing just doesn't really add to the music, it seems like it's just there to make the music seem more than it is. Lots of good stoner doom bands do only rasping vocals, like Horseback, Bongzilla and Weedeater. Don't stop working on the singing vocals though, like I say it can work it just doesn't complement the music as it is currently, it's clear the vocalist just doesn't have too much experience singing.
Anyway, the more I listened the more I liked it, and I don't know what your plans for the future are, but with dedication and hard work this could really become some interesting stuff. Check out stonerobixxx.blogspot.com if you want to distribute your music, it's a very popular blog and I think Robin will likely enjoy your style.