LGP grousers are great in mud and slush. If you are working in areas where dozers can easily get bogged then go for the LGPs, but if flotation isnt needed, then go for the narrowest grouser plates you will need. If you are in hard ground, such as in the mines, then having wide shoes will put a lot of leverage on the track bushes and pins, causing bad track chain life, tracks will lengthen quickly and you will get occaisional broken links.
You might get slightly more traction with wide plates, but the extra load will be transfered to track pins/bushes, sprocket segments, final drive, all the way back to transmission, push arm balls etc.
That said, I have seen some swamp dozers go in some REALY yucky stuff and not get stuck due to their LGP tracks.
. Just depends on the material you are working in. That would be the main advantage of the wide LGP tracks though - lower ground pressure for wet conitions, an LGP dozer can work on ground that you can't walk over. The extra width also helps in side sloping, keeping you from tipping over. The main disadvatage would be higher operating costs - not only the extra steel in the undercarrige, but increased fuel consumtion to turn it and usually shorter undercarrige life, especially in side sloping and on hard ground. They also have a smaller blade- they are wider true, but shorter resulting in smaller capacity. In my experinace the std tracks seem to push harder too. Generaly you should run the narrowest tracks that you can and still get the job done. If you are in ground that will suport a normal track width it will be harder on the undercarrige of an LGP machine, especialy rock, rock kills LGP U/Cs. They can certianly go places that a standard machine wouldn't dream of, but if you work in hard ground most of the time you are beter off with a std machine. All of my dozers are std machines, most of the work I do is in reasonably hard ground (when I do get into bad mud I have rented LGPs) and I can't justify the extra expence of running those wide tracks.