ADSL2+ Is it worth upgrading?

[#1]

BT is officially reporting that my exchange has been enabled for ADSL2+. The availability checker states that I can get 1.5Mbps on ADSL1 (which is my current profile), and estimates I could get 2Mbps on ADSL2+. However, from the internode graph I appear to be in the region where I will get no improvement.
I could request an upgrade to ADSL2+ to try and get an improvement in sync speed, but I've read of others having problems with ADSL2+ and as my connection on ADSL1 is pretty much stable and consistent I am reluctant to change since I understand that once I do so there is no going back. I would rather have a solid 1.5M than a flakey 2M connection.
So I'm really asking for some feedback from anyone with a similar connection to mine (~63dB line attenuation downstream) who has made the leap to ADSL2+.
Now that my exchange has been enabled, can anyone from Plusnet tell me if at some time in the future I will be forced to migrate to ADSL2+?

[#2]

Hi maranello,
At the speed and attenuation you describe we wouldn't recommend you to go onto ADSL2+ Mostly we advise customers on less than 4meg that they wouldn't see much of a difference.
At some point in the future you will probably be transferred onto 21CN but that doesn't mean you can't continue to be on the ADSL1 product. So, no, you wouldn't be forced onto ADSL2+
Jojo

[#3]

Hi Joanne,
Thanks for the advice and for clarifying the position.

[#4]

You're welcome, glad to have been able to help
Jojo