The HG 10 I can recommend from personal use If you must have Hi Def and in an HDD or Solid state format.
I dont think the SR7 is a lot different although reviews seem to put the HG10 ahead especially in its 25p mode ( which I personally dont think much of)
It however depends on what you mean by "low light" as any camcorder confronted with a room with a 60W incandescent bulb would be rather unhappy

. They all shine with better lighting and in sunlit outdoors
The best consumer lowlight camcorders are the tape based DV models ( as you can see)
Although the lens ( fast) electronics( good amplification with minimal noise) and sensor size ( the larger the better) play a big part. it seems that HDD camcorders, especially Hi def have to be very well sorted to compete with similarly endowed tape based DV models and up to a point HDV
All I can suggest is that until the models improve, it may be futile comparing them to your old miniDV but certainly as HDD Hi Def camcorders go, The HG10 is fighting tough.