Open Ports with Cable Proxy - just curious

Just out of curiousity perhaps someone has some expertise in this area.
I was just playing around with a device called an Alphashield testing out the capabilities for a security conscious friend ( with an open wireless network - go figure ?!).
The internet connection used was a high speed cable broadband connection.
A Linksys WRT54G router (firmware hack) or a Linksys unmodified WKC54G router ( I believe similar to the version 5 current Linksys WRT54G router) with the Windows firewall blocked most and passed the GRC and the Symantec online security scans.
That was with the cable broadband isp proxy off. ( list of proxies at www.askmarvin.ca).
With the proxies off the AlphaShield did not make much of a diffirence.
However with a more bargain router ( A Gigafast WF719 ) port 53 was open even with the Windows XP firewall.
The interesting thing is that with the proxy on the security tests lit up across the board. Lots of closed ports . It was pingable . Ports listed as open were 23,53,80 and 514.
It is just curiousity . Not that anything I am doing requires any high or even moderate security. Just testing the device .
The question is - is the information being released of any security thought or value ? Is it valueable information or such generic information that it is of little value or would lead a potential hacker off on a wild goose chase.
The proxy used can vary geograhically by a thousand miles.
There seems to an advantage to locking in the ISP proxy for reasons of speed advantages overall.
Any ideas ?

 

Thanks for the answer.
Guess the info identifies the isp I use but it is a big world with lots of users at the isp so guess the speed boost by using the proxy server with the cable broadband connection is well worth it.
For my internet use I would estimate the practical speed increase is about double the speed.
But I guess it boils down to what you are using your internet connection for - i.e. what content you are reading or files downloading and whether they are popular and are retained in the proxy server's cache.