Quote
XL170 - Second to Max-Speed for standard Urbies, but has net +0.5 tons for a small percent of speed from XL180.
XL145 - is the third to max speed for standard Urbies, but it has net +1.0 tons from XL180 with at 84 KPH which is around the speed of many mediums and fast for heavies.
XL125 - It has +1.5 tons from XL180, but it has the same amount of heat-sink as XL145. It only has about 72 KPH which is just a bit faster than many heavies.
LFE100 - If you are using XL100, you're being stupid, as the XL100 and LFE100 has same tonnage, but LFE survives one ST lost and has +2 free-slot. It has 54-58 KPH, which is around Mauler/Stalker max speed. It's stupidly fast, but you'd be with your assaults.
STD60 - Basically the slowest Mech ever, at 32 KPH, and will likely have standard-heatsinks to fit 8 of them. But you will have good amount of tonnage to mount something big.
I mostly use XL170 and XL145.
I don't see the worth of using XL180 unless if i could spare 0.5 tons and get +3 slots for my build. XL145 is enough for heavy weapons use such as LB10X and AC10. I only go down LFE100 and XL125 for really heavy ones like AC20, UAC20, UAC10, and Gauss for the lulz.