I feel I should balance my lack of walking experience with my extreme dislike of anything commercial when linked to a spiritual endeavour. I think the French route would be far too populated and commercial for me.
First, I should say although this is my first post, I benefited greatly from the knowledge shared in this forum. Thanks!
Three friends and I (all in the 60 to 72 year-old range) all started the VDLP from Sevilla on September 5, 2015. I think the timing worked out pretty perfectly in terms of weather - it was a little hot the first couple of weeks and a little wet towards the end, but we only had 3 days of miserable rain.
Unfortunately, we had 50% attrition on the "2015 Do Not Rescuitate Tour", one member had a back injury and another a serious muscle pull (which required medical attention). Both injuries were probably the result of simple bad luck. The 2 of us who completed took 42 days.
We stayed in some packed albergues (Mérida, in the rain) and were ocupado'd out of a couple by a group of about 20 Spanish car/bus/trailer assisted peregrinos - causing us once to sleep on a (clean) gymnasium bathroom floor, in Asturianos thanks to a helpful Hospitalero, since there were no other accommodations within miles. However, some albergues we had to ourselves - thankfully Lubian was one of these because there is a single toilet for 16 bunks. Others we shared with one or two other peregrinos.
I don't think we ever saw more than 30 total peregrinos in a day until we arrived in Santiago de Compostela, and that includes the 2 to 10 bikegrinos who would zoom by each day.
With 2 or 3 people, we were often able to get a room at a private hostel for very little incremental cost, which gave us more options where to stay, less contention for bathrooms, more flexibility on hours, and occasionally a heater some other way to dry clothes. Actually, for me, the most troubling thing about long days was not the walking, but the lack of afternoon sun to dry our laundry. Two of the really nice private albergues/hostels were Casa Anita (Santa Croya de Tera, Zamora), El Zaguán de la Plata (Fuente de Cantos).
Fortunately, none of us were picky eaters (or drinkers). This was good because although we had some fantastic meals, the Menu de Peregrino was often just some pork and fried potatoes. I felt really sorry for the strict vegetarians we met along the way who were living on Maggi noodles or Garbanzo beans and tomato sauce. Something important: you can almost always substitute Orujo for dessert or coffee - sometimes several glasses, which can be useful if your walking partner is a champion snorer. Don't miss 'Me Gusta Comer' in Rionegro del Puente, Zamora or La Bodeguilla in Mérida for lunch after 2pm. Something we found funny was restaurant and bar staff refilling premium spirits and wine bottles from large plastic bottles (in full view of patrons).
There are very few fountains with potable water along the VDLP – I always carried at least 1.5 litres of water in a Nalgene bottle (with SmarTube that I love), and a back-up of a store bought 500 ml bottle which I would refill. We typically tried to have a couple of oranges and a banana available for breakfast and lunch – I had a frequent fantasy about running across a bar for Café con leche after a couple of hours of walking (unfortunately it was usually just fantasy).
While people say VDLP is generally reasonably flat, there are some fairly steep and/or rocky up and downhills (coming down into Campobecerros and Laza, for instance). I would strongly recommend using two trekking poles and getting knowledgeable instruction how to use them before the Camino (also get some good rubber tips for use in towns). For the same reason, I recommend lightweight boots with ankle support rather than hiking shoes.
You will not regret any training that you have time to do in advance of your Camino. I was fortunate to have a flexible schedule for a couple of months before mine - unfortunately most of my nearby walking options were relatively flat. I worked up to 12 miles on some days, but then my wife said she had only approved my 2 month trek, not shirking all my responsibilities while training for it, too - so I had to cut back on the training a bit. I used the RunKeeper smartphone app for tracking my progress - train in Kilometers not Miles to save yourself mental math on the Camino.
I too, strongly recommend that you take a smartphone and get a local SIM - I used Orange and the coverage was very good - just make sure that you put enough money on the card so that you can renew after a month (there is no convenient way to add to it without visiting a shop and there are few along the VDLP). Almost any fairly recent smartphone (with at least 16GB of storage and the ability to accommodate Spanish GSM/LTE frequency bands) will do. You can store guidebooks (Gronze and Eroski) PDFs on the phone. You should get some type of offline map software, the free Maps.me app worked perfectly for me - it does not require network access to position yourself on the map. KMZ ~trail map~ files are available on the internet - they were not perfect everywhere because of changes to the route, but it is Extremely helpful just finding your way out of town in the morning. You can also download the Spanish language for Google Translate (so you can look up things from signs like 'Coto de Caza', etc.).
VDLP was my first Camino and it was a great experience. My friends had all done previous Caminos (or several). We met some experienced peregrinos who complained about the infrastructure on VDLP vs other routes, but we met some others who were doing it for the second time. If you want to avoid
populated and commercial, the VDLP is probably a great choice. ¡Buen camino!