I have a very limited perspective to share, as I'm a new rider myself, but I'll share it all the same.

Like you, I let my SO talk me into learning how to mountain bike. He's experienced; I'm not. I had long been relunctant to try it, thinking that I just didn't have enough dare-devil in me. So, when I finally decided to give it a try, I opted for a relatively inexpensive HT--a Specialized Myka. To be honest, I didn't research the purchase all that much and was only generally aware of the HT versus FS for a new rider debate. I just knew that I didn't want to buy an expensive bike only to learn that MTBing wasn't for me. I also immediately signed up for an all-women's clinic, figuring that this was the safest way to start.

This was last Christmas. I didn't get to ride on a trail for the first time until right before the clinic in June. By my second lap, I thought "wow; this is kind of fun." I then took the clinic and thought "wow; this is kind of fun, but I definitely have a lot to learn." So far, I've been on the trails every week or so. I live about 45 minutes away from the best local trails, so it's not something I can do every day, but every week or two is doable.

So far, the HT has been fine on what are labeled "beginner" trails. It's handled some technial stuff just fine, so long as I use good technique. To help with technique, I do drills once or twice a week at home. I have no basis for comparison, but I'm riding it and haven't gotten hurt or fallen yet (knock on wood). For reference, I'm 41 years old, 5'4 and 120 pounds. I'm in good shape overall, although I do have some issues with my hands and hips. So far, I haven't felt beat up or bruised from my rides. I've felt worse after road rides ironically.

So, overall, I feel like the HT is doing what I hoped it would do. That is, it's allowed me to get a feel for whether I like MTBing and whether I want to keep doing it (I do on both counts). For a $400 investment, I feel like I've already gotten my money's worth. It's not that I disagree with the advice to go straight to a FS, but I don't think an HT will prevent you from learning to MTB. I wouldn't buy one, however, unless I was comfortable with the idea that it's not likely going to be a forever bike.

That said, I definitely think the lower-end fork limits me to some degree (both in terms of weight and travel). My husband has a spare fork and set of wheels that we intend to put on the bike becasue they're both lighter than the bike's original parts. Do I think it's the bike I want to continue to ride as I ultimately advance to harder trails? Probably not. So, yes, I definitely intend to look at upgrading in the future. With what, I don't know exactly. I'm glad, though, that I now have some frame of reference when I go to test ride them. Since geometry is a limiting factor for me, too, I'll likely have to cross a lot of bikes off my list out of hand. That part is frustrating. Oh, to have long legs!

If you can, I'd try to take advantage of any shop that would allow you to demo bike. You might look for MTB events in your area, too, for demo opportunities. I'd also ask around to see what other women riders are using on the trails you're most likely to ride.

You might read this thread, too, for varying perspectives.