Dusko from Bosnia and Herzegovina had a high speed train travel from Istanbul to Ankara and then to Konya in October 2015.
I took afternoon high speed train from nice Istanbul’s district Pendik to Ankara. The travel was very pleasant. The route has large variety of landscapes. I enjoyed watching Marmara Sea as the train was leaving Istanbul’s surroundings. The train continues at lower speed through the mountains beside the river before reaching 250 km/h on high speed line all the way to turkish capital. It was very nice 4 hours of journey.
On Ankara-Konya route there is only high speed train so it was possible to do one day excursion from Ankara to the southern Turkey. I strongly recommend this journey to those who like me enjoy high speed travel. For very good price you can get ticket for business class and have excellent service on board that includes free drink and lunch.