What is the recommended number of Magento attribute option labels?

I have a store that has many attributes , especially the brand attribute which has more than 2000 brands & more will be there in the future .
Is it a good practice to have this much attribute labels under an attribute ? I just want to know the side-effects of the large number of attribute labels .

The things i faced so far was with the following vars (increased the values already):

the max_input_vars , post_max_size etc.

Personally I dont like to see the huge list in the page.Even the web page itself will freeze for few moments .

I really need some advice. The store is built on Magento 1.9 CE planning to upgrade to 2