I have noticed that my data speeds are... Slow. I mean 4-10 kb/s slow. Considering Dial-Up is 40 kb/s on average this is ridiculous to me.
I do use a fairly high amount of data, about 20-40GB per month, but when they say it will "slow down" I didn't think that it would mean dead stop.
I've been with TM for a little over 2 years now and this issue seems to be getting worse each month. On a good day I'll get about 950 kb/s, but these peek lows keep happening and usually for 2-6 hours at a time. This has happened each day this week at semi-random times, but usually it happens in the evening.
The T-Mobile app and base functions on the phone malfunction at that speed, causing the phone to try and over heat just to stay turned on.