Tight wad alert!!!

[#1]

I've been "upgraded" now for about 10 days onto the 60G version of broadband. W00t for me!
Since then, I've been experiencing the peak time slow downs which before I thought were a myth  -this forum for instance is taking a minute to finish loading a page.
(This seems strange to me, since before I was on the cheap as chips version, so I expected things to be about the same as before, rather than worse.)
Anyway, this has lead me to wonder (conspiracy theories about forced up-selling tactics aside) ...is there a way to trial the "Pro" add-on for a couple of days, to see if it's worth the extra money, before I blow the cobwebs off my wallet and break out *another* £5 / month?
(It's pretty much unusable during the evenings at the moment for anything other than IM!)

Much appreciated if anyone can help,
Paul.
P.S. My ancient Xyzel 6400 wired router seems to be moderately NAT-ing me, and I can't find anything in its manual to make it open. That hasn't changed, but I was going to give that a try to improve the XBOX Live experience if this Pro thing turns out to be a false economy.

[#2]

Product changes normally happen on your billing date so give it a try for a month from your next billing date and if it's no better switch back on the next billing date.
I believe 1 month is the minimum period.
Note: Browsing should not be affected by traffic management so maybe something more local is the issue. Have you tried a PC and router reboot?

[#3]

Yeah, multiple machines, multiple reboots (including router).
It can't be co-incidence that the only variable is the product change...

[#4]

Hullo Paul!
We'll have a look.

[#5]

Re NATing for XBOX live, we've seen that you get the moderate NAT message when the routers are set to use Symetric NAT, rather than Cone NAT.  I'm not sure if you've an option to change the NAT type on that router for it?