I recently traveled 3-4 times from Gujrat to Lahore.
1st time, I went through G.T Road (i.e. via Gujranwala,Muridke etc).
2nd time, I tried LSM (Lahore-Sialkot Motorway). The only feasible option is to take Sambrial Interchange (the start point of LSM from this side). For this, I had to take Wazirabad-Sialkot Road. This route could be better, if wazirabad had a bypass towards eastern side too, and also Wazirabad-Sialkot Road has a lot of big potholes.End result was that it took almost same time as if I had taken G.T Road. But this route is around 30km longer as well.
For next 2 times, I again shifted to G. T. Road.
So, my suggestion would be to stick to G.T Road. Go through Gujranwala city,, I mean avoid taking bypass.
I can only think of 2 advantages of taking LSM.
1- U will see (explore) this new route as well.
2- The scenary astride LSM is breathtaking. green crops on both sides is a treat to watch.