After the move, M-Net has not yet switched a "real" DSL connection, so I currently only have access to the Internet via 3G/EDGE. Since Congstar uses the T-Mobile network, reception is no problem - using the Speed Manager has kept the contingent of one gigabyte quite long. However, after the 3G "budget" was exhausted, the noticeable throttling came; there was no SMS informing about it, but it was clearly noticeable.
In order to be able to surf in spite of UMTS throttling with Congstar still halfway usable (for pure text websites it is enough to create a blog post as well) it helps to limit the smartphone (in my case an iPhone 4) to EDGE. Apparently it is still faster to use the slower transmission standard EDGE instead of using throttled UMTS/HSDPA. I'm curious how long this will work: the network operators offer an Internet flat rate with throttling, and not a UMTS flat rate with throttling, where EDGE delivers full speed all the time.
What are your experiences when it comes to mobile surfing with Congstar or T-Mobile? Or with other networks?