Hello!
As far as the dsl part of the router is concerned, even those supplied by PTCL itself are good enough ... it is the state of your telephone line that plays an important role ... even an expensive top of the line product can't help when the line is no good! The differences though small usually start appearing when having connections near the adsl2+ limit of around 24 Mbps.
When we had dsl service from ptcl, I tested many routers especially ones from uk lots though I am mostly interested in 'unlocking' the locked ones as shown at
ahmedfarazch.blogspot.com! That reminds me that I still have most of them around!
If you want to get any of those, let me know ... some have boxes and seem newish while some would be considered as 'used' ... I would recommend the
Sagem 2504n as it has a very good chipset and is quite similar to what ptcl itself provides but is more advanced with many extra options exposed via custom firmware ... it's wifi n 150mbps 'only' ... though it can be used as modem (bridge mode) with any other wireless router like Linksys E2500 v1 that I also happen to have ... such combo would cost around 2,000 or thereabouts!
Goodluck!
Regards,
Ahmed