The guy he quotes seems to be a hardcore nationalist, combining racism and Stalin nostalgia in the charming fashion of today's Russian youth.
Now the Montefiore quote I don't really like; he's estimating really high (up to 10 mln!), and bases his estimate on "many people of the 15 mln displaced probably did not survive". The only way for the former to follow from the latter is for mortality to approach something horrendous like Soviet POWs in German Camps. It had to be worse than your Arctic ww2-era GULAG by a noticeable margin.
Was there a famine? Yes there was. Did people die? Enormous amounts. Where did the displaced people go? Donetsk and Kharkov, probably. Most Ukrainian urban areas experienced high growth during those 4 years.
There was the 20s famine - all over Ukraine, Volga, Urals and Kazakhstan, as well as North Caucasus. People were killing their crippled children so that others could survive. There were cases of cannibalism, recorded by the nascent Soviet miltsia. With an equal amount of proof as the quote you provided I can say that this likely repeated during the 30s. That is horrible enough without the need to come up with mindboggling numbers.
I now Montefiore isn't the best source, but it's certainly better than a deviantart blog written by someone who is obviously biased. It sucks that I don't have Radzinsky's bio at hand. Granted, Montefiore is nicer to read (IMO anyway), but Radzinsky has more figures IIRC.
Can someone please quote a source that'll definitively proove this guy's either trolling or being a goof (which seems to be the consensus anyway).