any big advantage to using adjustable rocker arms

Solid cams require a valve lash (space between the valve tip and rocker arm when both valves are closed) that has to be set and maintained at a certain distance. That`s why an adjustable rocker arm is necessary. Solid cams are higher maintenance than hydraulic because you have to set the valve lash, but because the lifter they use do not require oil to pressurize them,they can rev higher with the proper valve springs without as much deviation. Hydraulics have the advantage of set it and forget it. If you`re just driving the streets then a hydraulic cam and lifters is your best choice. You can keep your stock rockers that way too.