Compared to other, larger, more established retailers Giant do have reasonable value but compared to the German online retailers not even Giant offers good value.
Of course there are disadvantages with buying the bikes online but I know with Rose, Canyon and Radon they do have shops you can visit to test their bikes, Radon is in Bonn and Majorca and Canyon and Rose are both in the UK now too. I’m not sure about YT.
Component for component there is no competition between these retailers and the established big players or boutique brands. That leaves the frame and overall design to question. Bikes from all the online manufacturers score very well in the press, Radon are probably the least well known over here but they are fairly large on the continent and get good reviews in the German press, plus their bikes are designed and welded in Germany.
In terms of All Mountain ive owned a Five, Alpine, Nerve AM and a Spesh Enduro I just bought a Slide 9HD, component spec alone is amazing for £2k and it’s the best bike I’ve owned in terms of its ability. But I was able to test one before purchase.