Here's a close-up shot of my 50mil prototyping matrix board. There is enough clearance between pads and I alternate a 25mil hole pad with a 35 mil hole pad so that I can still use 100mil header pins etc, but also 50mil as well as SOIC and other SMD parts on the board. They charge a little extra since there are 3,996 holes on each 3.75" x 2.75" panel and they are also ENIGed too. I will get 50 of these at least but possibly hundreds since they are so much better quality and cheaper than other stuff.
There is no wasted space on these boards, even in the corners since who needs to have fixed mounting holes when you may not even use them, or use rubber feet, or slots or just plain plug them into the P2LAB. For those of you who may wonder what ENIG is, it is basically the gold flash finish which is much easier to solder to and normally better for SMD work. The pads are plated through so they are plenty strong and 50mil connectors won't jiggle around since every second hole is 25mil. You will find that there are connectors that will be easier to fit simply because of the pitch without needing to drill extra holes and hacking the board.
I don't bother with power rails or any of that so called convenient stuff as it is inconvenient most of the time. It is just as easy to strip back some wire-wrap wire and tack it into place along the way so you can run it where you need. Alternatively I have used stick-on copper tape but normally that is totally unnecessary.
btw, I had to work this on Kicad since my Protel messes up the plotting of octagonal pads, so I exported to PCAD ASCII, imported into Kicad and saved it, then did a global search and replace on the 35mil hole pads in a text editor, then reloaded this back into Kicad.