Thanks for drawing attention to this. I wasn't aware of it before.
Subscription £1.67 + VAT for a month (= £2.00)
£9.17 + VAT for 6 months (= £11.00)
£16.67 for a year (= £20.00)
Too much for a miser like me, I'll stick to my dated but free MemoryMap and Anquet, but no doubt there are a few people on here with incomes who will jump at it.
Remember that includes all OS 25k and 50k GB maps, so it isn't like you're going to be buying mapping tiles on top of that - and for the cost of a Greggs coffee + sausage roll a month
. I do agree they mostly do the same thing, but for me it was a tool made useful when planning multi-day routes as you can annotate your maps quite heavily as well as load continental Europe (and further afield) maps - something I find a weakness with ViewRanger's online mapping tool, which seems to struggle with multi-day planning and any kind of 'to scale' printing. Additionally, if you do much winter hiking/mountaineering where you spend a larger amount of time in a smaller area you're able to print off up-scaled 25k/50k maps, for example 25k but double size for low-light conditions or navigation practice to emphasise the small features: which is something I picked up from talking to mountain guides and have kept doing since, especially as waterproof paper became conveniently available for home printing.
Bing maps has to be the most convenient free tool when you switch to the OS layer and have a few hours to kill and shines when you consider it includes the ability to switch straight from hiking-planning to driving directions to a parking place. But for navigation they provide OS maps with a noticeable offset (they don't orient north if you print them), which may not be an issue if you're following well marked paths in summer - but may become an issue if you're in clag and need to take a bearing and expect to follow it.
I'm not sure about Ordnance Survey's online offering but I've been told their subscription + toolset is excellent for those planning routes, presumably as they've recognised the writing is on the wall with their business model and without Lakes/Highland tourist map sales they'd likely already be going under. Whilst I do love having a full size map for planning across larger area, for practical hiking purposes I much prefer a 50k printout of the route and ViewRanger for a track/ability to locate myself to a grid. Only exception would be winter conditions where operation of a smartphone is difficult in snow/with thick gloves. As for not taking maps - I'd consider this mandatory, it takes about a minute to print a selection of the area you plan to be hiking in, weighs little and will save you from getting into a bad situation. I tend to annotate them, fold them up and put them in my diary to remind me of the trip - there is something about the epics where you end up having to navigate through hill thick fog in freezing rain by leap-frogging each other on a bearing for a few hours which makes you look back fondly at those maps covered in notes. Especially knowing that for those conditions smartphones are of limited use.