I've had some really bad experiences with the LNWR service. The advertised journey times with LNWR from London to Tamworth are around 1 hr 28 compared with the Virgins 1 hr 02, but the LNWR services have been short-formed, over-flowing with passengers and have run much slower than timetabled. One excuse was having to wait at Milton Keynes to change drivers, but there is no new driver waiting to take over because another service has been delayed.
Sometimes Virgin services are delayed too, trespasses on the line being a common reason, but you always have a seat and even if you're delayed you're still faster than the LNWR time-tabled timing.
Yes, the Trent Valley services are the best they have ever been, and that's reflected in increased passenger numbers, but additional fast Virgin services would be better than the current unreliable LNWR services. Why couldn't or wouldn't Virgin want these extra stops?