I think learning to service you own gear is a worthwhile endeavor for any diver who has a little bit of mechanical ability.
The HOG regulators should be no easier or harder than most other comparable designs (balanced diaphragm or piston first stages; balanced adjustable barrel poppet second stages). A few "special" tools are usually helpful (and easily obtained or improvised), and with HOG the rebuild kits are openly available to the consumer. With Scubapro, you need to search a little (ebay) or cultivate a relationship with a sympathetic shop or tech to obtain parts. Scubapro will not sell parts directly to the consumer.
This board and the DIY section are full of really helpful folks who can steer you in the right direction should you decide to service your own gear.
So, if you are happy with your current Scubapro reg, I'd say stick with and learn to service it, and work on parts "sources".
Or, buying a HOG reg, with parts kit, and learning to service it is an equally good choice...
Both choices involve learning to service your own gear.
Best wishes.