This is the only site I could find that gives you the gain of the amplifier. On that basis the SV9150 is better in that one sense. But gain isn't everything - if the device only detects a poor signal, no matter how much you boost it, the quality won't improve, and it's impossible to quantify the quality of reception from any of the specs I've seen (hardly any at all for the SV9150). And the amplifier itself might be low quality, but with high gain, just to help (not!).
Another word of caution - indoor aerials, especially for digital, only work well in good reception areas. Basically nothing can beat a good quality external aerial.
Try and find out from neighbours how they get on with reception, and what they use.