I went down the FTTPoD path, and it's ultimately a gamble on how long it'll be before Openreach foot the bill themselves (or some other altnet provider - e.g. in my case I've now got Cityfibre and Lightning Fibre rolling out in Eastbourne). I just had a leaflet from Cityfibre today saying they are building in my area soon and promoting themselves basically, but I'll be going with LF as soon as it's available due to the superior ping and most importantly it's a local ISP who seem to building a positive reputation. I pay rent and don't own the property, however I also went with the assumption that I'll be staying here for many years and it's better than the previous bonded FTTC connection I had (one of the two lines had an intermittent fault which was virtually impossible to sort out sadly). As I work from home, and host a server here, I wanted a reliable and speedy connection too.
Anyway, back to the topic... as you've pointed out the build cost is one of the disadvantages of FTTPoD. In the early days of the significantly altered FTTPoD charges the build costs were likely a fair bit cheaper than they should've really been. Mine if I recall was something like £3xxx range. If I had delayed it then it may have risen to perhaps double or worse than that figure. The other disadvantage can be the time it takes, unwanted problems may occur throughout the build process, and then making sure Openreach are stayed on top of. Cerberus did a reasonably good job of that back when I had FTTPoD done. You'll also pay a higher monthly cost on a 12 month contract and likely be limited to 330/30 unless you pay to end the contract early I guess. Other than that I can't think of any other major disadvantages.
Was it worth it? Yes. I work from home, I host a server from home and I wanted a speedy and more reliable connection. I took the risk that Openreach may roll out within the next few years as well as a local ISP and now Cityfibre. Also due to presumably Openreach overlooking not updating their database records for those connected to the same DP as me, as well as not promoting the availability of FTTP to those premises, I've pretty much had exclusivity for the last few years on this DP. I've not potentially been sharing FTTP if the GPON became 'busy'.