I used the Cicerone guide (parts 1 & 2) for my VF in 2019. The author of those editions (who has since departed, may she rest in peace) had a penchant for muddling up Left & Right which caused me quite some exasperation! From memory however, the trail is sufficiently way-marked on the half you are wanting to walk (through France is a different matter entirely...) to make up for guidebook lapses.
Cicerone are in the process of publishing a new set of VF guidebooks, now broken into 3 editions with a different author. Although I cannot comment on the accuracy, etc, of these as compared to previous editions, Cicerone are generally my 'go to' for walking guidebooks.
As with all guides, the author makes a huge difference...if you don't gel with their style or opinions (as I don't with a certain Camino guidebook penner), then it's usefulness or relatability will vary.
Best wishes & happy trails!
The Cicerone guides have been completely redone for VF by a new author Sandy Brown but I haven't invested in one yet but would require 2 books for GSB to Rome and one is not quite published. (I do have the older Cicerone guide which i found was useful in France to find shortcuts but there were issues with accuracy in places ) I liked the style in general of the Cicerone guides.
The Lightfoot Guides were updated last year and there is a single volume for the entire Italian section now, but it is a larger book than the Cicerone. The rewrite changed the structure of the guide to written paragraphs which seriously reduced the size of the guide. Maybe slightly better maps than Cicerone but I tend to rely on maps.me app on phone. It may have a little more info for places to stay.
I haven't used the Cultural Route one as it is Italy only and walking the other sections meant I never bothered with it.
The reality is all three are realistically workable for finding your way but each has their own style of communicating.... which makes it more of a personal preference. But it is wise to make sure you use some of the online resources especially relating to accommodation
I am a volunteer for the Confraternity of Pilgrims to Rome. I’m speaking for myself, but imo the best recent guide is the Lightfoot 2020 update. It’s available as an ebook , thus saving weight, and has plenty of variant routes which can save you time and distance on the “official “ route.
I walked part of the VF in Italy in 2018 and found it very well marked, sometimes three or four different groups placed signs along the same section of the route so it was pretty easy to follow. I also used maps.me which added confidence. The issue for me was lodging. Don't expect yellow arrows pointing the way to albergues. Like the author of "Where the Roads Lead" (a book about walking the VF) said, spending an hour at the end of the day wandering through a town looking for lodging is not much fun. English was not widely spoken and basic-level Spanish wasn't much help. That said, it was still a great experience.
The terre di mezzo english version was our guide plus we used gps maps which you can download from the vf european organisation site, those take care of the route and some accom. Otherwise booking.com will do for searching for accom. And the confraternity of pilgrims to Rome has accom. Lists.
If you were doing the whole route from canterbury the lightfoot guide has thebest directions for the less travelled french and swiss sections but the italian section is signed well enough that the terremezzo guide is good enough, though we used our gps and downloaded gpx route as an additional check when unsure. And we often followed our own route to fit with available accom.