"I have 4 GB" is kinda a flawed argument, just because your pickup can haul 2 tons does that mean you should ALWAYS haul around 2 tons of crap? Besides that, it's not really the static memory use that matters (for example, the guides TG loads up and then just keeps around), but rather memory churn (use a variable once, toss it out) that is killer. It's not hard to make an addon that *appears* to have a small memory footprint, but in fact eats through memory at an alarming rate. In fact many new addon devs make common mistakes that cause this.

Now, I've not dug deep into QH, but the fact it gives you a setting for how much "CPU workload" it uses concerns me on many levels. It seems to me that when you need a setting to throttle back your addon, it's became WAY too big... and probably in need of a redesign so that it doesn't use that much power in the firt place.

Oh and re: TomTom vs. Carto... TomTom is the only one officially supported. Carto support may break (has at least twice now), and it won't get fixed until I'm given a patch from a user for it. So, Carto's kinda "use at your own risk"