So...been over a year. Still, wanted to put my two cents in. If you're getting the smaller models I would say it's been good. I've gotten quite a few of them. Mostly in the Horus Heresy line. The issue I have is that a lot of their finecast is thin, giving it a bit of floppyness. The pour chunks, where they poured the resin in to the mold, will sometimes break off taking a chunk with it. This causes quite a few issues. The other problem is that they are bagged then boxed. Meaning they are pretty open to getting roughed up in transit. The bagging also causes another issue...they don't generally, if ever, come with any sort of instructions. Normally not a huge problem but as an example, I got the Death Guard Deathshrouds Terminators. The issue of not having an instruction booklet became an issue when certain arms designed to hold the Scythe two handed I used for the one-handed version, and then the scythes wouldn't attach properly to the arms. This caused me quite bit of frustration.
Now onto the price tag. If you're in the UK I assume the prices are astronomically cheaper, since going into a gamestore and buying it you probably get a bit of discount. Of course, being here in the states...paying for a 5 man Tactical squad of Horus Heresy marines costs about 23 pounds. However, that doesn't include the bolters for them...another 11 pounds and comes only in packs of 10. Now I have a nice blank slate marine, however if you want to get the shoulder pads that were specifically designed for your Legion...9 more pounds. So all in all...hugely over priced for what is a 5 man tactical squad.
So in short...they're extremely beautiful molds and models, and their details are insane...but pricetag and brittleness, and lack of instructions, causes you to look at it economically. Do you have the wallet to support FW, especially if you build an entire army out of them.