The bandwidth difference is like night and day. Waiting 30 seconds for a small thread to load when you have a cable modem gets really frustrating really quick, particularly when there are other forums that are lightning fast, and free. I read the subscription screen, and they seem to be quite honest about the fact that the hardware is up to date, they have just severely cut the bandwidth available to free users. I see no reason to disbelieve what they say. They don't state their motivations for doing this, but I think it is pretty obvious. The difference right now, is the difference between painfully slow (for free users) and lightning fast (for subscription users). You would think that would encourage subscriptions, but in the long run, I think it will just drive contributing users away.
I don't think it is a good idea, but they have every right to charge for their service. I have always thought that the AT forums were a little too good to be free, but the fact remains that there are other great forums that will still be free AND USABLE at the same time. I think the owners have to realize that with the free forums set to run this slowly, MANY users will leave for other forums, a few will just lose interest and come back less often, and a VERY FEW will pay to get the functionality they have become used to getting for free (up until the past couple weeks). The really great thing about AT is that you have super hardware forums, AND a super hot deals forum in one place. There are other super hot deals forums (like FW) and other super hardware forums, but the two together are a nice, unique combination. As for me, I will probably stick around, but come less often. I can't justify paying almost 10% of what my cable-modem costs to use one forum, as I frequent MANY forums (at least 5 or 10), and if they all did that, it would break me. I hope the forums make it, and don't lose too many users over this ill-conceived idea. Good luck.
Nack