I have a SH GX 2100E linked to my SH 300i plotter and it does all I ask of it.
The GX2100e does show targets as it can be set to various ranges, I keep mine on 10 miles, I mainly use it as a back up but the diplay on the plotter is excellant with many nice additional setting all of which can be personalised.
One big advantage of the GX 2100E is that you can just plug
it into your existing VHF
aerial (usualy ontop of the mast) and reception
I was also surprised at the quality and reception
of the 300i plotter as this is the first plotter I have had without it's own inbuilt aerial but again I cannot fault it.