The main problem with the guide rod lasers is they are not adjustable.
I think they are for the 1911, which the OP says he has.
I have a Lasermax on a pair of XDSCs and SIG P229R-all seem to be be spot on.
Gotta remember-on a SD gun they're not gonna be bullseye sights-they're for reasonably accurate COM.
IF the alignment is good great, if not, SOL. The laser grips you can adjust.
BUT...the guide rod laser may be more 'on target' over
varying distances than the grip type since it's closer to the bore axis-you can adjust the grip style to POI at only one distance-anything other than that, and you're going to be off.
With the guide rod, you only have to worry 'bout elevation changes-with a grip style, you have both elevation and windage changes depending on distance.
The lasermax requires two hands to use.
I can activate mine with one hand (use my trigger finger on an XDSC)-it's going to pretty much be on after that, as turning it off with the same hand is not possible.
So, what have we learned today boyz and gurlz?
Despite what some say, they is no 'best'-you have to weigh the pros/cons of each style and choose accordingly.