I have and use several Crimson Trace Laserguard sights on different handguns, including the Shields. I have no experience with the armalaser sight you mention. My experience with the CT Laserguard sights has been very good. Since CT will provide extra batteries once a year for their sights, I normally try to replace my batteries once a year, sometimes longer. I can tell when the red dot is not as bright as with a fresh battery. It is a bit more work to remove the LG sight to change the battery but it doesn't take long for once a year or so. I have had some that were not changed for close to two years.
I particularly like the CT laser sights with the activation button under my top finger on the grip. It works without concious thought. I can, with intention, loosen my grip with that finger if I wish to deactivate the laser for some reason (carrying the handgun through my home at night) and instantly reactivate it by tightening grip with that finger.
I do not use or pay any attention at all to the red dot during daylight hours. I use my sights. The only time I notice the red dot is during lower light or no light hours. I'm sure my daytime firing (at the range, etc) is done with the laser activated. But even so, my batteries last more than a year, so again, the battery changing is not an issue, and I do not worry about getting caught without an active laser. I generally activate the laser any time I load up every morning, and as I said, I can detect when the laser is getting dimmer and I immediately change the battery. My CT laser grips do have a total deactivation button whereas the laser guards do not, but that has been no issue for me since I never deactivate my lasers. If I pick up one of my house guns, I do not wish to have to remember to activate the laser understress. I expect it to come on if I need it under stress. And I check my house guns periodically as well as my EDC guns. So my experience with the CT products has been excellent. I highly recommend them. I like the fact that I don't have to push a button that I have to reach for. I like for the laser to come on when I grip the weapon and I have no problem with keeping it off if I think I need to do that. That's my experience with the CT products for what it's worth. You will have to have a holster that accomodates the Laserguard sights. The laser grips normally do not require accomodation. Good luck with your choice.