Must also say thumbs-up to FGW▸ for introducing a fast train at 17:40 from Maidenhead to London that now officially connects with the 17:06 from Marlow.
Not only does it allow a connection with the Marlow train but it should be a lot more reliable than the previous fast train around 1730. The train around 1730 came from Taunton and was fairly susceptible to delay, which often meant removing the Maidenhead stop. The 1740 comes from Oxford so should be delayed far less frequently.
For Marlow commuters the 17:30 from Taunton appeared to be timed to arrive in Maidenhead artificially early to avoid being an official connection (Maidenhead has a connection time of only 3 minutes which must be one of the lowest on the network!) so when the Marlow train was early into Maidenhead one could sometimes catch it with a bit of a run.
But yes, agree - the stop at Maidenhead frequently got cancelled due to late running and there didn't seem to be any other fast trains to London around that time.
From what I can work out, in the December 2013 timetable they swapped the Slough and Maidenhead stops between the Taunton and Oxford trains. As Southern Stag suggested, Maidenhead got the better deal.