Different dates for FTTC availability - best to be pessimistic?

[#1]

My exchange is Withdean, in Brighton. The Samknows site says there's an RFS date for FTTC of 1st December 2010, but the BT Infinity site says 31st March 2011 for my postcode and phone number.
I guess I'd better adjust my expectations and believe the later date. The frustrating thing is, there are a few new FTTC cabinets quite close to where I live, but they connect to the Hove exchange (which is actually closer to me than Withdean, but that's not the way the wires go).
The estimate given by Infinity is for 15mb/s download. Their estimate for ADSL is 6mb/s. I normally get an IP profile of 6.5 or 7 under ADSL2+, so maybe the VDSL estimate isn't too far out - so it won't be a huge leap in speed (although not to be sniffed at as long as the cost is OK).
Anyway, I probably don't have to follow the progress of the trial too closely, as it will probably be over by the time my local cabinet gets activated. Not that I know exactly where my local cabinet is. There are many green cabinets in the area, but 90% of them are for Virgin cable.
Graham

[#2]

Hi Graham,
The phone number checker on the BT site, or this one:
http://www.dslchecker.bt.com/adsl/adslchecker.welcome
are the most accurate. Samknows only has the exchange ready date whereas the phone number checker knows which cab it is. Openreach work by enabling a bunch of cabs ahead of the exchange ready date (normally about 10) then the exchange gets done and we can start placing orders on the first set of cabs, then they go round and do the remaining cabs on the to do list. For some exchanges that takes several months. Keep an eye on the checker as the dates showing as 31st October, 31st December and 31st March are pretty much placeholders and will move around a bit (saw one that moved by 3 months from December to September 2 weeks ago and we placed an order for them yesterday).

[#3]

Thanks Dave. That's very useful. The info at the URL you gave pretty much matched that of the Infinity checker, with a March 2011 date for my cabinet. I'll keep checking.
Graham