I put together a 15 watt maintainer with a small controller. I personally don't think that the actual 700mA output ( in full sun...less most of the time) requires a 3 stage charger/controller. At 700mA, and the partial rundown at night, I find that there is really little time that the batt is being "overcharged", when angle, clouds, and nighttime is taken into account.
Now, if you are talking 25 watts or more...I agree with Lewster about a better 3 stage charge controller.
Ive been using mine during summer "storage" times for 2 years now, and I find it to be just right. I have 2 group 29 Interstate wet cell batts.
Edit: I don't think the BatteryMinder was available when I bought.....That's a good price. I'd probably go for that one if I were buying today. Prices of panels are dropping steadily. I think I paid about $120 for my setup...and I think the BatteryMinder setup is better for not a lot more.
"If the women don't find you handsome, they should at least find you handy." - Red Green