Currently for 'local' gaming asdl is very good, but that could all change if local bandwidth is capped. Now, for a heavy gamer adsl saves a lot of money when gaming localy (no call charges as with dialup and isdn and disconnections), but there are fears that a local cap will just take this advantage away completely and to be honest, it wouldnt surprise anyone as it fits Telkoms 'profile' perfectly if it does happen.
As has been mentioned, gaming from SA using adsl and connecting to servers anywhere else in the world is very poor unless you sell a kidney to finance the 'unshaped' service which is marginaly better.
I am also not sure of what the latest is on the 'local cap', as currently in SA if you are capped it only affects your internatrional bandwitdh (after you are capped, kiss anything hosted overseas, servers or websites, bye bye till the next month). If they introduce a local cap and cut the connection off then adsl is uselss.
This is of course all speculation as the 'local capping' and cap limit have not been made clear as yet, only the intention to implement it (correct me if I am wrong please).
A game like Battlefield 2 will use around 30-50meg an hour during gaming I estimate so that, coupled with normal internet usage (or browsing and email as Telkom reps put it), and you will be without a connection in no time at all with a 3 gig cap.
Also take for example game patches and demos. Battlefield 2 demo is almost 600megs. Download that and 20% of your monthly bandwidth allocation is gone, bye bye, good night nurse. Toss in a std sized game patch or 2, linux update and,,,, you see where i am going with this right.
EDIT: Not to be all 'Telkom bashy' today, in their defence they have a wonderfull service for local gamers. They offer free gaming service ( SGS SAix Gaming Service) with game servers that you can join and they have a File Vault which is freely accessable to anyone where most of the new patches and updates are put up for download. You can also request a file to be put on the vault. Sadly as Telkom do NOT differentiate between local and international bandwidth usage when totaling the 3gig usage, most gamers only use this service 'after' they have already been capped internationaly.
I know of one bloke that moved to SA from the UK, promptly got adsl as he was an avid gamer. A man in his early 50's,(not all gamers are kids ye know hehe) retired and wanted to continue gaming with his squad overseas. Much to his dissapointemnt he discovered that the pings on adsl from here to his overseas server were in excess of 500ms wheres and isdn connection in SA would give you sub 300ms.
ADSL in SA is only good for local gaming, and only if the local cap is not enforced, or if the local cap limit is set very very high to accomodate this type of general usage. imho.