I use a magnavore magnet on my other 240, and have not had a problem with the green hard algae on my other 240. I only go over the glass about ounce a day, and sometime every other day. I don't have a high amount of light, as I'm not keeping any corals, and I'm sure this helps to keep the algae growth down. My buddy has a 300 reef tank in the wall, and uses the same magnet ounce a day, and hasn't had any problems keeping the glass clean. I know what you mean about placing frags though. I've helped my buddy a couple of times, and we usually have to scream back and forth as he's placing them. His tank is a tight fit, and he doens't have much room to work with at the top of the tank. I just made sure that on my tank I have plenty of room to work over the top, and that I could easily access the front side of the tank as well.
One thing that I'd add as far as cleaning the front glass is maybe a scraper with a long handle. I was looking at one at the LFS, and it does a really good job at scraping the glass, and has about a 3' handle.