Well I have to say that the expensive systems are pretty accurate but I didn't have the budget! I have an Ecowitt detector which gives me a reasonable indication of lightning in my area, yes I do get the odd false detection but very few. False strikes are more likely if you have an older property with old electrics or noisy washing machine of freezer as motors again can be problematic.and again if in a rural area electric fencing can be an issue. Initially it can be a bit trial and error to find the best position. I am happy with mine.
Stuart