I'm not an expert, but I'll give you my 2 cents...
That type does have carbon in them, so it may be giving some help in clearing the water. The carbon, as I have read, is only useful for a few days, so after leaving one in for a month I doubt it is being beneficial in that sense. Since the water runs over this type of pad I doubt that it is as helpful as something where water runs through it. The Blue part of the filter does catch some of the larger crap floating around in the water if you tend to over feed food cubes and stuff like that..basically it can't hurt, as I see it. The Bio wheel itself has mixed reviews, some say the eclipse tanks are really built for fish only setups and the Bio wheel becomes a nitrate trap and to remove it. If you have live rock working for you already, I would probably agree with this assumption. The set-up isn't great, but it works and many people have had success with them. With the price of the pads not being to expensive, I'd just change em out as you see fit. The wheel is a personal choice, on whether to keep it in or not. I run this type of system myself on a 29. I wouldn't do it again on the next larger tank, not because it doesn't work, but because the filter/pump system takes up to much room on the tank enclosure and upgrading lights can be a real pain in the but, excluding too many options...
Good Luck,
Billb