ral
Android Expert
EDIT: I used the DS SD card to flash the ROM, and most likely would need to make it a gold card. My question is, what's a gold card for? Is it absolutely needed? When I've rooted my phone, can I take out the gold card and substitute it with my old SD card?
I know you need it to flash a generic RUU on a branded device and you can create a new one if need. But I will have to pass on this question.
How much better would ICS be over GB 2.3.5?
ICS has a nicer user interface and some apps like Google Chrome are ICS only. I could live with either one.
And is rooting the phone permanent? If I don't like the changes, can I just revert everything back?
You can unroot a phone and revert to stock.
But, if you are already rooted, rather than unrooting the phone, I would advice that you just run a ROM like Android Revolution HD 6.3.3. It is like 100% like the latest Desire HD stock ROM with performance tweaks.
I would advise that you not rush into this. There is no reason to do it right now. Browse these forums. See what people are doing with their rooted phones and decide if it something you want to do.
Good thing is your phone is working. Maybe take a breather first

