Gazelle edge--How long is a good workout?

Most programs recommend starting out at 20 mins. for a minimum of 3 times a week and gradually increasing at a rate that is comfortable for you. Also, if you have any health problems you should get approval from your physician prior to starting.
How do you like your Gazelle? My husband and I (40ish) are thinking about getting one but I'd like to hear from people who already own one.

I have a Gazelle, a treadmill and a recumbent bike. I use them all but love my Gazelle.

My Gazelle went into the back part of the basement for our Christmas party. I think it's time to pull it back out. When I was starting on it, 10 minutes or long enough to really start huffing just didn't do it. I found that I need to go until I actually sweated. I know that sounds gross, but the 20-30 minute mark was the best.

Lately my blood pressure has gotten much higher, though my weight has been stable (still far, far too high) for a few years. One of my doctors is having fits about it, so I'm hoping a few times a week on the Gazelle will help me bring it back under control. I do not want to turn to medicine yet. However, I'm extremely sensitive to sodium. Still, with good home eating (use menus from savingdinner.com) and exercise, I really believe I can get my BP down and avoid medicine.

I bought a gazelle edge glider in 2003, and I love it. I use it 20-30 minutes twice a day 3-4 days a week. Just recently the display module has stopped working , would desperately love to get a replacement. I am in my seventies and this is a good way for me to get in the movement I need.