If you look closely at the warranties of SSDs, you will notice that they are shorter than their traditional Rotational counterparts. Flash has well known issues such as write speed degradation with time, and a very limited lifetime for every cell. I think one of the wiser approaches is to use flash as a non-volatile cache, so that when your flash crashes, so you can have the peace of mind that your data is safe in a traditional hd while enjoying the speeds of flash.