I was actually agreeing with you and defending your honour Miss G [for Grumpy]. I mentioned 'earlier V20.11 EU DEM' because there were actually 2 in 2010, both with version 20.11 but with slight variance in the Part No. [D224900AG013 and D224900BG013]. The earliest was the larger sized V20.11 with header date 23.04.2010, the next was the more-compressed V20.11 you've mentioned above with header date 16.09.2010 and the latest is V20.12 header date 10.01.2012. Both the later V20.11 [your mention above] and latest V20.12 [aka D2249750A.IMG with Part No. D224975AG013] have same size of 317,841,408 bytes, same 288 maps [as does the earliest V20.11], and therefore the map content is the same in all 3 DEM maps. Stands to reason if the earliest and latest have the same mapping data then so does the intermediate one. Doesn't matter whether NT or NTU detail map is used with any of the 3 maps regardless of the original source of the DEM, i.e. supplied with a non-unicode or unicode version unit as you said. The header date of the first V20.11 of 23.04.2010 aligns with the April 2010 release of 3790 which originally had NT EU mapping factory loaded.

From what I can see, the 2nd V20.11 and V20.12 are identical apart from the header info date & P/No. Although the first V20.11 has the same data as the other two it's just less compressed. In short, it doesn't much matter which one is used. The larger map may draw a little quicker if space isn't a problem.