It is important to realise that the shuttle bus to T2 from the Fernbahnhof runs in 15-20mn intervals though, you must build in some time for that too. I've had instances where I arrive just as the navette departs so just hiked to the Skytrain (it was pouring rain too #Germanweather ).

DB is extremely reliable. Your 2.5 hr buffer is plenty in Frankfurt. While trains ARE occasionally late, cancelled or re-directed to other tracks, DB keeps you well informed. Connections to Dresden are frequent, so, even if you miss the planned train, there is likely another connection just about to leave. After arriving in Europe, Germany in particular, I rarely rent a car and never fly.

Agreed! Didn't ask the precise amount of time because he knew better and felt embarrassed.

I think you got plenty of satisfying answers but let me just confirm these as I live in Dresden and have been on this route plenty of times. The train is usually on time except when there are signal malfunctions on the route which can sometimes lead to up to ~30min delays (which wouldn't be problematic in your case). The only reason for a problematic delay would be a suicide attempt by someone on your track which fortunately doesn't happen too often but has happened a couple of times when some relatives of mine were traveling. In general though, the direct train shouldn't pose a Problem.

Thanks! It's reassuring to have a data point from someone who actually lives there.

Reliability of DB is terrible (I have to travel around 700 km per week on them so I know) but you should be save here.

Note that in case of a cancellation or an expected delay of over 20 min, you can take any train and even use a different route. Suppose the 6.10AM was cancelled and the 7.10AM substantially delayed. You'd still be good.

You flight is not an intercontinental one. It's sufficient to show up at the gate as late as 2:45PM. You would need about 20 min to get from the airport long-distance train station to BA's checkin counter. The Priority line there is usually short. From there, with a US passport, you can use the automatic passport control gates. The line there isn't too bad usually (I'd say 15 min is close to a worst-case scenario). And the security check is right before the gate and shouldn't take long, either.

As the OP got satisfying answers to his question, I think we can go a bit OT.
No DB is not extremely reliable. They are somewhat reliable. A search on your favourite search engine will reveal plenty of press articles in German and foreign press about how DB has become a national shame due to their poor reliability and customer service.

It is all relative. Compared to what we have in the UK they are extremely reliable

I disagree. OK, Northern sucks but at least there are days when everything runs perfectly; I have never experienced a day where DB has run the trains I wanted to catch perfectly. I'm talking about days when I plan to take 5 to 10 train services. I probably spend as much time in the north of England as I do in Germany. Yes, this is a big generalisation.

This whole thread is a massive generalisation, with little help for the OP or others. We can all chime in with our anecdotes, but that does not help in the specific instance. Of the last 20 ICE trains I have taken in the last two months, for example, two were delayed by more than 15 but less than 30 minutes. The rest ran pretty much on time. Is that useful for someone who takes a train next week? No. Germans complain massively about DB but for the most part the system runs well enough get people moving. Of course it could be better, and it should be, but it is one of the better national rail services in the world. I will grant you that the reputation that Swiss and German train punctuality enjoys abroad is not entirely 100% correct.

So I’m at FRA now waiting for my flight to London, and 3 out of the 4 trains I took during this trip were on-time within 3-4 minutes (or precisely on time). The last train, which took me from Dresden to the Frankfurt Airport, was more or less on time until we reached Frankfurt am Main Hauptbahnhof. There, a passenger needed medical attention and we had to wait ~15min until paramedics arrived. Afterward the train resumed its journey and we arrived at Frankfurt Airport with a 15min delay.

All in all, pretty impressed with the German train system. It’s not clockwork like in Japan, but everything was efficient, cabins were quiet, and the seats were comfortable.

I do agree with that, when it works it works really well. The train themselves are very comfortable, I never upgrade to First Class on an ICE as I found second class really good. In contrast when I take the TGV I will take First Class as much as I can.

I took the ICE yesterday with a connection to a regional train. The ICE was about 10 minutes late and I thought I'd missed the connection, but they held up the regional train so that all the connecting pax could make it.

But then the regional train with the destination Strasbourg announced that the final stop in Strasbourg was cancelled. I guess it was because of the strike in France, but there are no French employees on the train. I noticed that some trains went all the way to Strasbourg that day, but not mine. Someone asked a DB agent if there was a refund, but he said no. We could take the tram from Kehl for €1.80.

If you arrived at your final destination with more than one hour, you are entitled to a refund of 25% of the fare, regardless of the condition for delay. My TGV Mannheim - Kaiserslautern was cancelled yesterday and I took the RB one hour later, I will fill the form for compensation.

Great. very useful. Thanks!