I have been swapping emails with the horribly well-informed John Medhurst about Barbarossa to Berlin. Here are some of his thoughts:

I have also had a solo go through with Barbarossa to Berlin and got a German
automatic victory in 1943 due to finally pushing the Soviets over the edge.
I am still not 100% on the rules though and am still finding things out.
Myself and Dave have whisked through to Winter 1943 (i.e. beginning of 1943)
and things are looking OK for the allies at the moment but Dave is playing
more cautiously than the actual Germans and the Fuhrer has not yet taken
command. I have kicked him out of North Africa and am holding him on a line
from in front of Moscow down through Kharkov to the mouth of the Dniepr. He
holds 4 VP spaces at the moment - Minsk, Kiev, Odessa and Sevastapol. He has
played Taifun but none of the other space attack cards. I have just got
some of the Russian mechanised fronts on the board so I feel that the
Fascist menace is under control but it is not as overextended as in the real
world so I wonder whether I will be able to knock him down to zero if he
plays Totaler Krieg. The strong point for the allies is that they have
played quite a few of the longer-term cards including ASW victory, US
build-up, Lend-Lease and so on. I have not yet played any invasions but
Dave is also looking quite strong with almost all of his units up to full
strength. I have been playing up to 3 RP cards a turn to keep the Soviets
intact.

My overall impression of the game is that it is much more bitty than Paths
of Glory - there are a lot of special rules and a lot of cards that have
quite dramatic effects - like Totaler Krieg. There are a lot more combined
event-action cards which at least makes the events more likely but is
possibly a bit of a 'no-brainer' compared with the agonising decisions of
Paths of Glory. I also find the events happening out of their real world
order a bit iffy. Compared with the First World War the second was rather
more in the way of the steady application of overwhelming force. Things
happened at certain times because that was how long it took to build up the
necessary forces. So Normandy was not possible until the U-boats had been
beaten - it took months of shipping troops across the Atlantic that would
have been much too dangerous against an unbeaten U-boat enemy.

All in all though it is a good game and Dave also seems to be enjoying it.

Well I'm not surprised John is not 100% on the rules - they are a bit of a moving target with Ted Raicer publishing new errata every few weeks. This is my only gripe with what is otherwise my latest most favourite wargame.