Titan cord vs power cord for tag line

I'm looking into buying a lightweight cord to use as a haul line/ rappel line to be used along with my 9.2 sterling nano for alpine ascents. My primary goal is to be able to make full length rappels without carrying a second climbing rope. Currently, I use a mammut phoenix 8.0 for this, but I want something lighter, more compact, and less dynamic. I think I have it narrowed down to the 5.5mm titan cord from Bluewater, or the 5.9 power cord from Sterling. Does anyone have any experience with, or reccomendations about these or similar cords/ materials? Thanks

I bought the 7mm Sterling Tag line (75m) to pair with my 70m nano. The extra 5m makes up for the stretch of the Nano. The 7mm works great for my purposes but they also make a 6mm that sounds like exactly what you are looking for.

Edelrid is due out with a rap line that's likely ideal for your wants.

Thanks for the repies. For practical purposes, I think the suggestions you guys made make the most sense.

For anyone else interested, I just spoke with Edelrid and according to the rep, their new rap line II 6.5mm,($170) weighs 25g/m and has a breaking strength of 10 KN. A 60 m cord would weigh 3.3 lbs.

The Sterling 6mm tag line,($261) weighs 27.6g/m and has a breaking strength of 14 KN. A 65m length would weigh 3.95 lbs.

The Sterling power cord is heavier than I originally thought. Sterling does not list the weight, but a retailer lists a 50m section at 1.8kg which is 36 g/m with a breaking strength of 19 kN. A 60m section would weigh 4.76 lbs. unfortunately, you can only buy it in 50 or 100m lengths.

For comparrison, the mammut rap line 6mm, ($190) weighs 31g/m and has a breaking strength of 16 kN. It comes in 60 m length which weighs 4.1 lbs.

The most impressive cord I've looked at online is the Bluewater Titan 5.5mm. It weighs 18.4 g/m with a breaking strength of 13.7 kN. A 65m section would weigh 2.6lbs (60m 2.4 lbs). Unfortunately, it is only available in 50m lengths at $214. I spoke their sales mgr. They can make 100m spools, but will only do so if I purchase 5 of them. I assume they are close to $428 a spool, but i did not ask. I could justify 100m by cutting a piece to go with my 30m 1/2 rope for ski mountaineering. If 4 others are interested, I would go with this stuff. Otherwise, Edelrid seems like the way to go and I dig the color so that's a bonus. Thanks again,

Justin