I think Unication does a great job with their G4 and G5 pagers. They do seem to perform well with simulcast systems. However, they are intended as pagers, not scanners. While they have a lot of programming flexibility, they don't have the operating flexibility that a scanner has. HOLD and AVOID are features that are being tested in beta software, but the public release doesn't have those features yet.
I have a Unication G4. I also recently bought a Uniden SDS100. It also performs well with simulcast systems and it has more operating flexibility than the G4. I bought my SDS100 from Remtronix as a factory refurbished unit for noticeably less money than a new one.