The Aurora is a sport touring bike. The geometry is a mix between a cyclocross/touring bike. Chainstays will not be as long as on the LHT. (Longer chainstays prevent heel strike when doing loaded touring - esp. on smaller frames.) The Aurora has STI shifters which some people love (using barrel adjusters to make gear/shifting finetuning adjustments) The LHT has friction shifters (bar ends) that allow for greater adjustment of the front derailleur and fine tuning. The Aurora has canteliever brakes and so does the stock LHT. The crankset on the Aurora 50/39/30 - a mixed ratio for speed and some low gears for small hill climbs. The crankset on the LHT - 48/36/26 - a slightly lower gearing for touring and lots of hill climbing.
I own an 09 Aurora and while I enjoy it okay. I much prefer my 520. Touring bikes are about simplicity. Have you ever seen an exploded diagram of an STI shifter?? Sheesh.
It's pretty daunting. I live somewhere hilly and the 520 handles hills like a frickin' champ. I dread hills on my Aurora - the gearing seems either to high or too low on steep hills but never just right. Both are good bikes. Only you can really make the decision on if it will ultimately fit you or work for you. We can only offer our humble opinions.
"Things look different from the seat of a bike carrying a sleeping bag with a cold beer tucked inside." ~Jim Malusa
2009 Trek 520-Brooks B-17 Special in Antique Brown
2010 Surly Long Haul Trucker-Brooks B-17 Standard in Black
1983 Fuji Espree Single Speed-Brooks B17 British Racing Green