It's a guess really. As Kitz says, the 7800N has excellent performance and a well respected chipset, but every connection is different, so you can't be certain until you try it.
Another good option would be the Billion 8800NL which has an even newer Broadcom chipset, and performs very well. It would also be future proof to an extent because it's also VDSL2 capable.
[Typo corrected]