Luxilon ALU Power and Luxilon Original are both worth trying.
I think many of the poly's compared to Luxilon ALU should be copared to the Original version instead. SPPP, for example, seems like it is almost exactly the same as Lux Original, except for the first few hours. Like most Luxilon Strings, it has amazing playing characteristics for the beginning of its life. There is a time period where you don't feel like it is possible to hit the ball long, or to hit it without lot's of kick to it. I've never gotten this feeling with anything other than Luxilon strings.
The Original is not as crisp as Luxilon ALU. I don't know if it is safer for your arms and shoulders or not, but I would say it is a little softer. It is definitely more durable than ALU, Luxilon will freely admit that. It is also lower power, just like BigServer1 said...
Both strings have incredible bite, but for some reason Luxilon Original is rarely mentioned around here. It is a great choice, a great starting place in someones quest for the ultimate string.