We have both Fibertel (via Multicanal) and Arnet also in a load-balancing and fail-over configuration. If one goes down our router automatically switches it to the other. Internet is essential for our work, so this setup works best for us.

Both our connections are supposed to be 3gbps downloads, and we get close to that rate often, except Fibertel does slow down significantly more during peak hours and also has more latency issues than the DSL connection. But just as captdave says, we get better speeds with Arnet DSL (most of the time). However, when it comes to reboots, we have to reboot our Arnet DSL modem at times (maybe once every 2 weeks or so), while rarely have to do this with the Fibertel cable modem.

If you're not sure you're getting what you're supposed to; you can test your connection speed online at http://speedtest.net -- Choose a server outside of Argentina (eg., New York, Washington, San Francisco) to test against, as this will give you a more accurate usage result than testing against the local Argentina server (which will always be faster).

Fibertel (BA <-> DC):


Arnet (BA <-> DC):