Our first reaction on unpacking this rack (supplied, like most, in kit form) was, 'Where's the frame?' You get wooden legs, glass shelves, and a pack of bolts and bits. And indeed that's all you need.
The legs bolt up to top and bottom shelves and the middle shelves are supported on the usual little widgets, which fit to a selection of holes in the legs, making this a flexible design. Putting a load on the glass in this way is basically perfectly sound practice, though we're not sure we'd like to try a really hard sideways push on the top shelf, especially if loaded with the recommended maximum of 40kg.
If, then, this is not the ideal rack for those with hyperactive 10-year-old kids, it does look very, very attractive. You get a choice of finishes on the solid hardwood legs, a choice of grey or clear glass, and the added-cost option of 'iRAP' acoustic dampers for each shelf, making it the 'XL4 Acoustic' version.
As ever, we have doubts about how much the rack influences the sound of the equipment placed on it (LP players apart!), preferring to believe that it's simply the presence of a somewhat resonant object like this in the room that's audible.
And it is audible, but not objectionably so: we detected a slight added 'bloom' in the midrange and a small loss of precision in the tonal definition of instruments and voices. We would definitely not recommend this as a suitable support for any turntable, but for line-level applications it balances looks and (lack of) sound very nicely.