After a few months of research and asking questions I opted for LaserLyte Sub Compact Laser Sight. I have had it for a few months now and love it. It functions better than advertised it puts a bright red dot on your target in any lighting conditions except bright direct sunlight. Even then if your target is in the shadows it will light it up. I would not rely on it on a clear sunny day but just about any other time including overcast days or any indoor lighting condition target acquisition is instantaneous. It lists for $149. but I got it for about $90 and change at my local gun shop, East County Guns. While at the gun shop I compared it to the Lasermax UNI and the Insight X2. Obviously it is much smaller than the Insight X2 which has a flashlight that I liked but it did not have a laser only option which I did not like. The laserLyte was brighter than both of the others. LaserMax's rail mount Uni Laser is about the same size but made out of plastic with a big LaserMax emblem on it. Looked gadgety to me. The LaserLyte Sub Compact Laser Sight is CNC machined aircraft grade aluminum simple rectangle shape with the edges beveled to prevent snags. K&D Holsters has no problem making a holster to accommodate it. To me it looks like it was made for my XD.45 compact. You can check it out at LaserLyte Sub Compact Laser Sight. Below is a pic of it

As you can see it is tiny
Here it is on my XD

There is a screw that mounts to thread thru the rail slots. In this pic I had used the middle one. Later I learned that if I used the forward one it lines up and sets flush with the gun's edge. Makes it look more like part of the gun if that matters.

The only issue is you need to put blue locktite on the adjustment screws or it will lose POA. Mine lost POA after about 500 rounds without the locktight. To para phrase a gentleman on another sight the adjustment screws are about the size of a ant's nuts so it is a pain to get it sighted right took me about 20 minutes or so. Since I added the locktite it has stayed solid as a rock.

I had an issue with it the last week. When the battery was getting low it functioned as advertised and the red laser dot pulsed for over two hours before dying, I left it on to time it. Than, I hogged out the screw while replacing the battery. I figured I would have to drill the screw out or use an easy out. I called LaserLyte to see about getting a replacement screw. Before I got done explaining the problem the lady had my name and shipping info. Than said a new one was on its way to me. No questions asked! Except that she asked that I put the old one in the prepaid envelope that would be with my new LaserLyte and send it back to them so they could figure out what happened. Never have I had better customer service. This is a great well made product with premier grade A number one customer service. I got the brand new replacement laserlyte as promised on Friday including the extra set of batteries. I would rate LaserLyte customer as VIP premier customer service as I can not imagine how it could be any better. Lisa even sounded pleased to be able to send me the replacement like she was doing me a favor.