I read a little about sinit to understand why one would use sinit. If your goal is to have an init with a minimum amount of lines of code for the init, I think it is best in the world. If you have any other goals than this I think you will find many deficiencies. It appears to me that any little thing that may go wrong it trips this system to shutdown rather than fix itself. It is like a ball made of bubblegum. S6 by comparison is a mountain made of diamond.
You can try Void if you like, but in the long run you will be back or miss obarun.
PS This was written many years ago and I believe at the time he didn't know that much about s6, and 66 wasn't around then. The rest pretty much have stayed the same.
http://troubleshooters.com/linux/init/features_and_benefits.htm
Keep this site bookmarked if you want to learn more linux than you already know.