if seats are modified like Garuda Plus it will become best and useful train.
I guess this will be most preferred train as an alternative to bus. At present, Super Luxury buses(APSRTC-Non AC- push back) costs Rs. 820 from Tirupati to Samrlakota whereas DD costs Rs. 770(which is AC-same reclinability). So, las minute pax will always prefer this train compared to buses. If one wants Garuda-like seats, they can go for 3A.
If the seats are modified the seating capacity I'll be decreased from present 120 to just 100 as they have push back. One more thing shatabdi seats are like garuda plus with greater push back and comfort. At least if they use seating like in chair car the comfort can be increased without compromising on seating capacity of bogie.