The total element count is what matters (forms/fields/buttons etc.)
If you start a client it will download the solution once and never again (if no changes are made on server) the solution is stored in the userdir/.servoy on windows like "C:\Documents and Settings\<yourname>\.servoy" so you can check how big it is as file to give you an idea.
Performance tip: for use over the internet use SecureSocketLayer (enable via the admin page) this will speedup the download (compress the solution) and all the client/server data transfer is secure.