Rendezvous,
I recently did this route from Pune to Hyd and Back. I started at 8.00 am in Pune from Pimple Saudagar, its 3 km ride to MPEW and reached BHEL at 6.00 pm in my M800. I didn't cross 80kmph as I prefer this speed in this car.
Now coming to my experience of the road,
From Pune to Hyderabad- Till Indapur, you would not feel heavy traffic and after that around 20 kms later, a narrow bridge of 0.5 km will eat away your time. If is raining be very careful ast it is filled with lots and lots of pot holes, which will scratch your cars bottom badly.
Even though, the 4 lane ( Or may be 6 lane I am not that sure..) construction is under progress, you are open to either one of the side which is a stretch of say 3 or 4 kms patches which are very good and I enjoyed them. This I did on 4th Nov morning to reach home for Diwali. Try not to miss the bypass in Solapur to skip the city traffic.
Now coming to your interest,
Hyderabad to Pune back - I started at 9.00 am on 14th Nov, A sunday. This delay was due to some last minute shopping for my Uncle in Pune. I found both the shell pumps in Habsiguda and Ameerpet closed. Hence filled with IOC in Dishuknagar finally. I suggest you to fill at Shell in Raidurg, which near BHEL. I got 20.7 Kmpl with 80% A/C when I was coming to Hyd on 4th.
Now coming to the road conditions, till Zaheerabad, there is no major issue, but be care full in Zaheerabad as two wheelers come from no where in the main road in the 2 - 3kms stretch.
I further suggest you to start at 4.00 am as you will cross Zaheerbad in the early hours. From there you find pretty okay roads. No much fuss. Once you reach Sholapur outskirts, you need to take right to by pass the city. Pls confirm it with some one. After that, the road is okay. You can touch Sholapur in flat 5 hrs. Lesser if you cuise at 100 kmph.
But, before you reach Indapur, there is a narrow bridge of apprx. 17 feet, a tight fit for two trucks with loads. This is some 25 kms before you reach Indapur. We got stuck here fore more than 2.5 hrs. as a Tempo carrier broke down on the bridge and the tracffic was strictly one way. I might be longer if I dindn't manage by going the worng side where ever possible. Just don't go with the trucks lane as they generally don't move away from the sepentine queue.
Most important thing is pls make sure you
cross this stretch in day light as it was tough for us when it was raining and my cars headlamps got a thick layer of mud slung from other vehicles. The visibility reduced drastically.
Once you cross Indapur, the pot holes frequency starts increasing except on the new road strecthes. As Auto B suggested, the SH 77 and 70 ways are okay when I made trips last year to Kholhapur, but IMO, its a bit longer.
I didn't find any great places for food in between when we ( My better half was with me while returning to pune) stopped before Sholapur for lunch.
I again suggest, due to the abrut rains, pls reach Pune before the sun sets, as the roads are not predictable in the night.
Hope this helps till you reach Pune safely and then to Mumbai.
On the other hand if you get delayed anywhere, you along with your family are always welcome to take a pitstop in my home and return to mumbai the next day.

. I stay hardly 3 kms away from the Express way.
Sorry for not uploading the photos as my camera display screen broke just before I left to Hyd from Pune.