Couldn't find a proper solution but monkey patched it like this:
Post.solr_search do
facet(:comments_count) do
row('No') { with(:comments_count).less_than 1 }
row('Yes') { with(:comments_count).greater_than 0 }
end
case params[:comments_count]
when 'No'
with(:comments_count).less_than 1
when 'Yes'
with(:comments_count).greater_than 0
end