If your worried about tube life in small signal tube don't they last for a very long time many years if not decades, some of the good ones are even rated for many thousands of hours 20,000+. I use my mac tube preamp everyday for both music and TV watching its on 8hours + a day with zero worries about tube life so don't sweet that part at least.
The other point i suppose is just nice for a change in sound.
I've not heard of another tube pre with a switchable SS section as well, other then the Freya +