Storm, ETOPS and Confair are the agencies. They do not provide too much, only a small amount of sick pay, rest is up to you. You get 8% on top of the salary for social security. You are paid in Euro.
The local contracts have everything paid; pension, social security, retirement, in the country which you are based in. You are paid in the local currency.
Tax is paid in Switzerland for both methods, and if you have to pay something for your "home country" you have to fix that yourself.
The last items are almost the same thoughout the network, the only thing is holiday paid which is depending on the Hungarian Labour Code for local contracts, and around 24 p.a. for the agencies mentioned above.