Mine is OK with no foot room too, but I'm going to put an overhang on when I swap the breakfast bar top for a proper top. I suspect that if you are working higher up off the bench, so not leaning over as much it'll be more of an issue, but nothing too problematic.
When I did my bench I spent ages making the strongest joints I could, before filling the sides and bottom with 18mm MDF panels, these are primarily so that I can fill it with drawers as part of my plan to add mass, but I suspect they mean the joints don't do anything anymore!
Traditional bench design pre-dates MDF, where creating an equivalent resistance to wracking would be expensive and time consuming, especially in the days before people had time for hobbies and everything was done bare-minimum and back to making some money. Nowadays it makes perfect sense to make use things like MDF to quickly and cheaply add strength. Your design isn't going to wobble, but if you needed to make it stronger I would do that.
If you really need more mass, the quickest and cheapest approach would be to fill in the bottom with an MDF shelf, wrap 4" of pine around the bottom to create a well, then fill it with concrete! Though I suspect just piling the space full of tools will be enough.
I built mine and haven't done the top yet, partly because I wanted to use it first and get a better idea of what I wanted first and partly because it took me ages and I was under pressure to do some more useful work. Anyway, one of the things I was undecided on was a tool well or some sort of tool put-down place, because on the one hand it's really useful to have tools to hand, but on the other it's really annoying to have tools getting in the way all the time and clutter on the bench. This one solved itself as my next job was to put up some stock shelves and I realised that if I pilled the top three shelves with all my spare timber and kept the lower shelf empty I can use it to keep projects on, but also use it for putting tools on when I'm working at the bench. I think this is a pretty good option as the tools are to hand, without being in the way.
I designed my bench with a very deep top, so I can work form both sides, using the vices etc on once side and being able to setup my small powertools - sander, morticer, mitresaw etc on the other depending on the job. I'm planning to do the top using a length of Ikea's finest (well they're second cheapest) kitchen worktop for the powertool part and some hard-wood for the 40cm or so behind the vice. Extra depth built up using MDF, so it'll be cheap and nice all at the same time. There's no benefit in using hardwood for the whole top, it's just extra planing!
I'm still toying with the idea of using an M16 tap to cut threads into the top for all the work-holding, though I need to play around with this to see how well it would stand up to abuse.