Well, to answer my question... I did have a good potter about on the MMTS trains around Hyderabad and Secunderabad.
They're fairly typical of Indian urban railways, although in a modern version, and severly underfunded, leading to woefully inadequate scheduling, particularly in the rush hour. This, combined with a major bottleneck at Secunderabad Junction (and some ancient signalling) means that delayed long-distance trains can severely back up the MMTS - I was on a 40-minute delayed service (I'd actually turned up early for the next one), which is pretty bad for an urban service with a roughly hourly headway.
The trains themselves are pretty modern and impressively clean EMUs (with some connecting DMUs on outlying services). The doors generally stay open - again, fairly typical, although quite terrifying at some of the higher, unguarded overbridges, when it's crowded (and hanging out a train door is one of the great pleasures of travel in India - although you do have to stand your ground to keep the spot). Although their top speed is very restricted, their acceleration is rather impressive. Most of the train is general carriage, although half a carriage per rake is women-only, half a carriage permits vendors (so that's where you go if you're thirsty or hungry) and less than half is first class (reportedly very badly enforced).
Buying tickets is half the battle. If the station also sells general SCR tickets, it'll be a melee just to get to the MMTS counter (often on the platform). Forget queuing - you have to thrust your money into the cashier's hand (although most fares are Rs5 - about 6p). There are some machines, but they only accept local bank cards. You can't buy tickets in advance (they last 2 hours), so the ticket queues often lead to people missing the (relatively infrequent) trains - the closer you are to departure, the more aggressive the queue/melee becomes. There is also a daily women-only service, which is very badly patronised, but instigated due to the sad volume of sexual harrassment (unpleasantly euphemised as "eve teasing").
Off-peak, and at weekends, it's mostly fine, though, and a very pleasant way to get through this crowded city - you see so much more of local life on a train. At peak hours - particularly between Hitech City and Secunderabad/Nampally, it's terrifyingly full.
Hyderabad is typical of the recently expanded Tier 1 cities. The expansion has been around "Hitech City", but in the form of individual campuses. The local government doesn't want to upset investors by making it difficult to set up there, but at the same time, with India having only 3% of its population paying tax, there is very little money for infrastructure. Much of it goes on building big flyovers (as this is where foreign investment goes).
There is now heavy investment in public transport - well, as heavy as it can be. The current state of the MMTS is a stop-gap until major expansion, signalling improvement, purchase of new rakes/bogies (to use local terminology) can be afforded. There is also a 3-line metro system under construction - the first phase also centred on transport from the old cities to Hitech City (the Hitech City MMTS is a good couple of kms from the offices, meaning there's a phenomenal load of bus and shared-autorickshaw passengers going that way).
Safety is horrendous. Despite Hyderabad's terrible, and aggressive traffic (and lack of pavements - they get half-built, damaged, have things dumped in them, then basically abandoned, so you end up walking along what's basically a busy highway in the dark), the tiny railway actually manages to attract more casualties than the roads. Trespass is the primary reason for this (although the railway blames level crossing users wearing headphones, which seems to be rather missing the point), but the cling-to-the-door culture seems to cause a number of deaths too, as people fall down the gap when running for a departing, full train, and overestimate the distance of the OHLE poles. Security, though, is high. Expect WTMD at any sizeable station, and X-ray machines at the largest, and a military/police presence throughout. Hyderabad has fresh memories of bombings, and this is largely how India has reacted since the Mumbai attacks (not least because of the vast pools of cheap labour).
It's fascinating to watch this country develop, and the MMTS is a great microcosm of how it's happening. It's no wonder it's popular when it takes 20 minutes from Hitech City to Secunderabad, vs a minimum of 1h30 by road at peak times. But it's unreliability is forcing people to move to expensive accommodation out by the offices. I thoroughly enjoyed my visit to Hyderabad - and my time on the trains there - and wish the city all the best.
