Just addressing your external standard motion sensors, have you tried to reduce their field of view by focussing them more on the target area.
I'd really love to see the results you'd get running X10 via HomeGenie with the W800RF. I've tried the CM11, CM15 and CM19 all with excellent results but don't own a W800RF to try.
So are you throwing down the gauntlet?
I may do it but would have to dedicate the W800 to HG, so would be an exercise where I am willing to drop HS. (May happen unless HS4 has some great new features.) Trouble is I have 157 devices and 124 events to reconstruct in HG. Truthfully, as an old geezer, my motivation is waning, although HS4 may ramp it up.
Don't get me started on age
No excuse!!!!!. In fact age and retirement is the best time to embark on a hobby like this.
No need to migrate anything from HS to HG yet. A Raspberry Pi,a simple installation of HG on an SD card is all that is required. When that is done all that is needed in HG is to create two widgets(devices in HS speak) one for your motion sensor and one for you light, plug your W800RF into the USB port, install the W800RF MIG(plugin in HS speak) and you're good to go.You can then test the W800RF and standard motion sensor's efficiency.If you like what you see you then have choices.
Adding 157 additional can be done gradually while HS is still working away.In fact both systems can work in parallel. In fact you can actually off load the X10 responsibility to HG which can do all the hard work and pass the results back to HS.Spoiled for choice
I won't get into the nuts and bolts of HomeSeer here as I'm purely discussing X10 but from what I'm seeing HomeSeer is becoming over bloated and performance is suffering as a result.Style over substance seems to be the order of the day and do bear in mind that X10 is not officially supported and if Mark decides to walk there's few who will pick up the X10 support baton.