Why people say what level technology will X or Y have its really difficult to answer because "technology" is such a broad field. Still I'll try:
Medicine/Biology.
Continued Nazi human experiments push this forward a bit in certain areas (e.g. effects of toxins, gases, radiation, cold, heat etc.). Post discovery of DNA (which should be around the same time, a few other people were close) they are going to chuck buckets of money at genetics at the start to prove Aryan superiority, but they may not like the answers and stop spending. Or maybe they'll try to create the Aryan superman and be light years ahead of us, its difficult to tell.
For genetic diseases (e.g. Autism) they are going to be far behind us as Zyklon-B will probably remain the "solution" in this field.
So Nazi-world will be ahead in certain areas, behind in others.
Rocketry.
Probably ahead. They had a good start, top quality personnel, who can train more top quality personnel, its military useful (after the A-bomb comes along) and it plays to their small-penis compensation needs. Also they are probably going to keep chucking money at it in a way that the SU and USA didn't after Apollo 11.
Computers.
Behind. Up until the 70's the Nazi's are going to keep up and while they'll start off behind the British and Americans the uses are obvious enough that they will expend effort here getting early mainframes. But come the PC revolution they are going to be in trouble. A regime as totalitarian as Hitler's is going to be dead opposed to the PC. They will restrict the market to just top officials and the government meaning it will never get as big as it did in the OTL West post 1970. Lacking the billions of dollars Intel and IBM have made selling computer chips to ordinary consumers they aren't going to be able to fund the research to make Moore's Law possible. Just like the SU in OTL they are going to lag in this.
Other Consumer Electronics.
Millions of miles behind. The Nazi's didn't like the free market, they believed in top down co-ordination of efforts and they cared more for bombs than for butter. While they'll probably be better than the Soviet Union but you are not going to get a Hitler-pod.
In general I suspect a Nazi world will be a more militarised world, meaning that certain fields will be ahead and others behind. But as a more militarised world it will be a poorer world, meaning it will be a more backward world. Because the Cold War showed that American teenagers wanting to play Ms. Pacman are better at driving development of computer chips than Soviet Military Procurement bureaucrats.