usual comment for use of “no brainers” applies
There are no real no-brainers left tbh, all the ones that haven't been done yet have some major work required that nobody wants to pay for. But among these, if we look at potential reopenings that would have a significant impact on large numbers of people, Ivanhoe has the potential to outperform pretty much every regional line reopening since privatisation, as the population catchment is so high.
How you make the most of the line is a tough question to answer though. On paper it's fairly straightforward (provided that a link to Leicester main station is funded): the line passes right through the middle of Coalville town centre and gets fairly close to central Ashby as well. Given how rare it is to be able to affordably build stations in urban centres, this
would be a great opportunity. The issue is that these large intermediate towns are low density, car dependent sprawling places, without very much tourism potential. Therefore without much potential inbound traffic to these towns, and everyone wanting to drive to the station anyway, chances are that a centrally located station (and the car park that would be demanded alongside it) would do more harm than good. This means that until declining Leicestershire towns experience some sort of cycle/bus renaissance, you'd probably positively affect more people's lives by going for out-of-town parkway stations with enormous car parks - though this obviously isn't particularly forward-thinking so it'd be fairly heart-wrenching to watch them go for this option while passing up on the rare opportunity to build a 21st century city centre station (that isn't tunneled).
Furthermore the fairly abysmal urban transportation in Leicester makes the 'Cardiff model' fairly attractive - where you build a short section of urban tramway to complement a suburban rail project, a compromise solution that sacrifices passenger comfort, long-distance rail integration and network simplicity in order to get some sort of tram system underway in the city. In an ideal world, Leicester should just have a separate tram system handling the urban/suburban traffic, leaving the Ivanhoe to be a regional connector. But we're not in an ideal world, and I don't see Leicester getting funding for a standalone tram anytime soon, so I could see the Ivanhoe as an opportunity. With no guarantees of a decent alternative in the future, it would seem counterintuitive to not build as many stations in west Leicester on the Ivanhoe as possible, even if it slows down the line.
However, IMO given the great long-distance connections at both ends of the line, I think the negatives of going for tram-train may outweigh the positives here, unless there's a genuine guarantee that a proper Leicester city tram network would be developed out of the Ivanhoe tram-train section (think Sheffield but in reverse). Plus, even if we disregard the journey time penallty, running on-street through most of western Leicester would mean avoiding the King Power Stadium, which is deserving of a rail connection, and I don't really see how you could get a tram-train from the mainline south of the stadium into Leicester city centre without anyway building that very expensive heavy rail spur.
