that 2Mbps is actually megabits per sec, not megabytes per sec. so, you have 8 bits in a byte, giving you a max of 256kilobytes of data throughput. max means if all your neighbors on the same node are doing nothing at all and you are. if youre all downloading the same movie at the same time, youll be sharing that pipe with everyone else. this is the downfall of cable systems. DSL doesnt have that share fallacy, but it also doesnt have the high speeds like cable. my cable is listed as 12Mbps cable, but i am hard pressed to get more than 700KBps max usually. it can burst at about 1300 or so, but the nominal is never higher than 700.
so no, you dont actually get the numbers they advertise.speed tests are a good way to see how good the conn is, but if you do the test when no one else in on it, youll get higher speeds reported than if everyone else is using the node with you.