Comp 3 is more rugged.
T1 claims 50k hours (thats almost 6 years if left on!) on setting 8, but I had a battery go dead on setting 12 after only sitting in the safe for 2 weeks.
That's interesting about the battery life. Is their quoted service life only for the lowest settings?
If not I'd guess bad battery as well. Or possibly a defective optic. Might be worth looking into, since I'm sure they'd repair or replace it for you if it's not working as intended.
To address the OP, I'd go with the 2 MOA. What I have now is a 4 MOA (Though not a T-1, I'm poor.) and it's great for short range, but beyond 100 yds it just covers too much target.