I use the old maxis prepaid broadband package now, rm89 (rrp rm99) 1.5GB 30 days validity. I got 3Mbps and quite stable, but after 1.5GB won't be able to surf and need to pay for a new pass.

What's the capped speed on maxis postpaid broadband if I exceed the quota for the rm68 3GB package?
Can I use the modem that I got from the prepaid package with the postpaid sim?