It's a bit unfair to say it's unrealistic, since Norwich, like many of the other places moddeled in PC-Rail, isn't controlled from an IECC, so actually, a sim-sig version would be unrealistic to (and infact, since sim-sig is an IECC simulation, but he can't simulate IECC due to the contract with NR, no Sim-Sig simulations are going to be "realistic"). Sadly no-one has created a signalling simuation that accuratly represents a real NX pannel, which AFAIK cover most of the route milage in this country. AFAIK, the track layout on all the PC-Rail sims is perfectly accurate, as are other important features. The mechanical signalling simulations on PC-Rail are very realstic, and I don't know of anything that simulates them as well, with block bells and everything. My only real critisism is that it that their simulations are quite expensive, especially considering the quite low milage covered, but perhaps we are spolied by Sim-Sig being free.