The Garmin GNS 530 and its smaller sibling, the GNS 430, are, I think, the optimum bridge between the old IFR navigation system and the future. If you choose, you could operate the Garmin navigators as nothing more than navcoms. That would be a terrible waste of capability; nav and comm functions are there and you can dial the frequencies just like any other radio.
You can also use a 530 in the same way as a conventional GPS navigator for guidance direct to the destination airport, or any other point on the globe. Many pilots find it easier to separate direct guidance from the airways, intersections, SIDs, STARs and approaches that make up the complete IFR system. Those who feel that way can fly the direct part of the trip using the 530 as a GPS and then revert to raw VOR/LOC data in the terminal area. But when you become comfortable and familiar with a Garmin 530 or 430, you will find that you have complete mastery of the total IFR system in a single source. You will find that the "procedure" key and the flight plan button allow you to fit perfectly into the IFR system without ever dialing a frequency into the nav receiver.
I recommend that pilots new to the Garmin equipment first familiarize themselves with the flight plan function. A press of the flight plan button calls up the function no matter what other modes are selected. You can easily insert, delete or modify in any way the flight plan as your clearance changes, as it does on virtually every flight. Learn to use the flight plan function on every flight, even when it is a short VFR "direct to" trip that could be flown by pushing the "direct to" button. And if you have two 530s, or a 530 and 430, everything you enter or change in one flight plan can be automatically crossfilled into the other navigator. This is crucial in IFR flying because you can have only one clearance just as you can have only one assigned altitude or heading, no matter how many different navigators or displays are in the panel.
Once you have the flight plan function mastered, you are most of the way toward fully using the 530 in your IFR flying. For example, if you are cleared to fly an airway you simply enter the points that define the airway into the flight plan. If the airway bends at an intersection, that point must be entered in the flight plan; otherwise you need only the VORs that define the airway. When the controller hands out a shortcut, you can simply call up the flight plan page and go directly to the new clearance point further down the page.
The next feature to study to use your 530 for IFR is the "OBS" button. When you press the OBS button you have transformed the 530 into a super precise VOR with no need to dial the actual VOR frequency. Not long ago the controllers at Akron Canton Airport cleared me to intercept the 092 radial off the Findlay VOR after takeoff. Findlay was the first point on my clearance route, so the FDY identifier was already in the 530's flight plan. By flying direct to FDY, pushing the OBS button and setting the 092 radial on my HSI exactly as I would with a VOR, I was on my way. If you remember that the OBS button converts the Garmins into virtual VOR receivers, you can use the equipment in any phase of IFR flying, though intercepting and tracking specific radials is becoming less common every day.