The EL2 is probably the best of the EL series. Nikon finally started using a flex circuit, instead of having everything hardwired, like they did on the EL/ELw cameras. The meter uses SPD cells, instead of the older CdS cells of the EL/ELw. It's essentially an FE in a Nikkormat form factor. That said, I'd rather go with an FE, since they are much more common, so if something breaks, there's more of a chance of a parts body which can donate the parts necessary to fix it. It also can use the MD-11/12 motor drives, which are an improvement over the AW-1. To counteract the weight issue with the MD-11/12, I use the energizer lithium AA batteries. They've the side benefit of adding a little extra speed to the frame rate.
With respect to the AW-1, if it made a quacking sound when fired, the nylon gear was stripped. That's also a common problem with later MD-2 and the MD-3 motor drives for the F2 series.