I've been on the Volvo B5LH hybrid 4 times (3 x ANE308) (1 x GNE21) and although the Hybrids suit the 21 due to the fact that they're stopping at nearly every single stop and the fact that the distances between stops are few and far between also warranting the use of Hybrids on the 21, the 308 has some very long stretches of 50+ roads to deal with such as Links Rd and the Coast Road and including the fact that the 308 doesn't stop as much as the 21, and drives for long distances at times, it makes journey times slower for the 308 compared to the 21 which is timetabled to stop at every stop. Another issue as well is that due to the GNE version having a high roof, the aerodynamics are slightly better due to a more rounded front and the top of the back.