Voting is a simple, automatic process. Your wallet would have a pop-up when you configure it asking what you want your vote to be and giving a bit of education on what the option actually means. After that the process can happen entirely automatically. Submitting a vote doesn't cost you anything in time or money and unlike leaving the decision 100% up to miners it ensures that entities like the Winklevoss twins with the connections required to get access to mining hardware on a level playing field, BTC to BTC, as you are. (Mike Hearn for example has said he expects for mining hardware to be highly regulated in the future)
The problem with your proposal is that it counts anyone creating transactions on clients that don't have this voting feature as voting for the permanent 1 MB block size limit, which is a very controversial departure for the original plan to eventually replace what was meant to be a temporary 1 MB block size limit with another solution that allows high bandwidth nodes.
If all votes require a special transaction type, rather than counting normal transactions as a vote for a particular option, that would be more reasonable.
Others, including myself, have said repeatedly we don't want the tiny set of large pool owners setting the blocksize. With voting both parties can be made happy.
Very few people are complaining about the vote by mining method. Large pool owners aren't the ones making the votes, as miners can point their hashes to any pool they want.
In any case, I don't think proof-of-stake voting is inherently bad. It's just that the implementation has to be unbiased to the options.