Hi all,
Thought it best to share my discovery in a new thread to maximise the impact.
Recently I found that there's an issue with the Vodafone Connect (or Huawei HHG2500) with concurrent uploads/downloads. If you upload a big file to the internet (say, a video to Youtube), you'll notice that you won't be able to surf the internet at the same time (but your upload will still continue), and neither will any other device connected to the network at the same time. This is due to an issue with the firmware (version 1.6) in the HHG2500, which won't be resolved until November/December this year.
Being unhappy with the fact Vodafone won't let me use my own hardware, I called Vodafone Broadband customer service and told them this is unacceptable, and asked to either let me use my own equipment (ha!) or terminate my contract early, and if neither happen, I'll go to OFCOM about it.
They tried to roll the firmware back to v1.59, unsuccessfully, so agreed to let me terminate my contract early with no fees.
Good luck all, and happy net surfing with your own kit again when you get rid of that blasted VF Connect Modem Router!