The DOUBLET or G5RV ,if a certain length, is a GREAT multi-band antenna though don't let the term RANDOM LENGTH fool you as it refers not to just any length ,but one that is not some multiple part of a wavelength on any of the Ham,or other bands.The best lengths I have used for 'random' are 17,25,34,51 and 84...pretty much multiples of 17 will be safe length as long as you choose a length over 1/4 wavelength of the lowest frequency that you expect to use.
It also pays to choose your length of ladder line in the same manner and have a good tuner and 4 to 1 or higher ratio balun. Internal antenna tuners are not capable of tuning a random length antenna to ALL bands as they often only tune a 3 to 1 ratio and you need a 10 to 1 tuning ratio or better usually found in manual and some automatic antenna tuners like MFJ and better LDG tuners.
Doublet antennas are great as long as two supports are available and you have time. The W3EDP or ZIP-ZEP single wire antenna is better suited for rapid,easy, deployment but the doublet or random length dipole is a better choice for many as it has the edge on performance.