What is the subject of 其他的都很满意? I found the following translated example:

除了没有电梯，其他的都很满意。
Chúle méiyǒu diàntī, qítā de dōu hěn mǎnyì.
I am satisfied with everything except for there is no elevator.

I have a question about the subject of the second part of the sentence. Which of the following interpretations is correct?

The subject 我 is omitted, 满意 means satisfied (such as in Yabla) and 其他的...都 is the topic. It literally means:

其他的(我)都很满意。
I am satisfied of every other thing.


The subject is 其他的都 and 满意 means satisfying (though I could not find this entry in any dictionary). It literally means:

其他的都很满意。
Every other thing is satisfying.
I am glad to see this interesting question. The omission is really one of the most confusing but fascinating parts of the Chinese language. My explanation would be almost similar to your first one.
There are two omissions in this example. One is the omission of the subject. The other is the omission of the verb.
除了价格以外，（我）（对）其他的都（感觉）很满意。
Except for the price, I feel very satisfied with every other thing.

除了...以外 - except for
价格 - price
我 - I
对...感觉 - feel
其他的都 - every other thing
很满意 - very satisfied