I've not fully read the review yet, but it seems they don't think you could buy better at the price.
Probably top value for anyone with digital only sources and just a power amp, that also needs a good headphone amp - especially if they have DSD files.
If you've read the DAC posts of others on this forum you may have seen the opinion that DAC differences are often only subtle - more subtle than the differences between most other components. I agree with them, though I've only tried DACs costing no more than £600.
I had the Audiolab 8200 CD player on home loan and as you may know, the DAC section of this player is the M-DAC, complete with its optical and coaxial inputs, which gave me a chance for a combination of CDP / DAC comparisons.
I fed the (coax) digital output of my Marantz CD6000KI and the (optical) output of my Humax Freesat box through (what was effectively) the M-DAC. Now the Marantz is a KI modified, old but nice sounding CD player but I expected an improvement from the M-DAC. I heard no improvement.
The sound of the Freesat box was improved by the M-DAC. The difference could indeed only be described as subtle but the sibilance on satellite radio was noticeably smoothed. Not much money would have gone into the DAC stage of the Freesat box so anyone could have expected an improvement when bypassing it with a 'best buy' DAC costing £350 more than the Humax.
In fairness to the Audiolab, this was a relatively short test and 'subtle' improvements are often more fully appreciated over time. Ultimately though I'm not rich so couldn't justify the £600 cost of an M-DAC for the improvement I noticed.
By all accounts there have been worthwile improvements to the M-DAC+, not least to the all important power supply (now within the main body as opposed to the previous 'wall wart') and I would like to hear it especially with DSD material.
I needed a USB DAC and in the end went for the (no longer available) Epiphany Acoustics E-DAC for under £100 which sounds OK, especially with 24 bit files but on 16 bit stuff does not better my CD player - which will come as no surprise to many of the other forum posters.
Good luck with your research, don't get too taken in by review superlatives and if you get the opportunity of a home loan, take it.