I've purchased a few HTB systems for friends from Fluance. I will tell you that the HTB system is the best $200.00 speaker system that i've heard. When I first ordered the system I was a little skeptical about recommending them but the buyer only wanted to spend $250.00 for the speakers so the Fluance set fit perfectly.
Once he got the system, I came over and helped with the placement and setup. I first noticed how heavy the main speakers were, especially for their size. The build quality was much better than you'd get from any other offering at this price or even up to $350.00 and will be comparable in the $500.00 range.
The sound out the box was very thin and cold. I told him that he should let them play for 24 hours and we'll come back and get the placement right and calibrate as well.
After 24 hours of playing in his basement, the speakers no longer sounded harsh and thin but quite enjoyable. They did not sound like $200.00 speakers at all. Of course these speakers aren't the holy grail but they will not dissapoint the buyer who has an entry level receiver worth$350 to $500.00 in my opinion.
I have since recommended these speakers to a few more friends and clients and have installed about 3 other systems using these speakers since and all involved were happy then and still are today.
Although these are not the exact speakers that you enquired about, I think that if the HTB system represent the bottom of what the company offers then I think the SM938 could be worth the small investment risk.