As one of the pellet grill users here, I thought I would speak up.
Haven't used the Lousiana Grill, but it is the same basic design as the Traeger, which is what I, and a couple of other people here use.
I believe that Traeger is no longer represented by a distributer in the UK (someone will correct me if I am wrong), but their old distributer is now importing
Green Mountain Grills.
I have used neither the Lousiana or GMG pellet grill, so don't feel I can give a recommendation. However, I have looked into both of them previously (on the web), and I believe the GMG is the better spec'd, and is cheaper too.
From the little information available on the web about the Louisiana, it appears that its controller is a
timed mechanism with the various settings calculated to give you the required "low", "medium" and "high" settings. In this it is like the original Traeger - this works well most of the time, but because there is no feedback from a thermal probe, extreme weather (either hot or cold) will affect the grill temperature - i.e. here in the middle of winter, my Traeger is currently running quite cool.
The GMG has a more sophisticated controller, which has both a grill temperature probe and a meat probe. The former is used to adjust the feed of the pellets to keep the temperature on target. It also has a low-pellet alarm, which warns you when your fuel is running low. That would have saved my bacon a couple of times! The meat probe doesn't affect anything, but it does display on the controller which is nice.
An GMG optional extra is a remote controller, which means you can monitor and adjust your grill from the warmth of your home.
As I say, this is not a recommendation, but only to make you aware of the choices. I was well tempted by the GMG, but decided to pimp my Traeger instead, and add my own control mechanisms.