i been thru Core V1, 250d, Node 304, Cm130.
All temps are good except cm130.
here's my breakdown.
Core V1
pros
Good airflow
flexi placement of panels. for best cooling, let the gpu have the vents.
fits small to mid size aircoolers like cm hyper 103.
small size.
cons
no cooling for drives but it's near the vents so not really an issue.
build quality is average but it's only $70.
no dustfilters.
Node 304
pros
airflow doesn't look good at first but surprisingly, i recorded the best gpu temps in this casing. maybe it's the material?
fits a 212x air cooler. rare for an itx case.
good cooling for drives with intake fans blowing directly. again, rare for an itx case to have this.
got dustfilters.
great build quality. sturdy and materials feels not cheap man.
cons
psu intrudes the space of the gpu slightly. can fit but it's tight. also not good to have the psu wires touching the gpu pcb, but with a backplate, its ok i guess.
best psu for this case is Seasonic G series as the cables are at the bottom and the gpu won't contact it.
or u have an itx small gpu size card.
expensive at $130.
250d
pros
the only case to have fit a dual 120 radiator.
great airflow
easy tool free build for drives. most fan mounts.
got dustfilters
cons
quite big size. so a bit play cheat here. cmon its supposed to be itx.
build quality soso but price is ex.
Elite 130
pros
fits the longest gpu easily like the Sapphire toxic series. The rest also can except core v1 but damn difficult and not recommended.
im ok with the cable management, just tie them to the sides.
cons
terrible airflow, maybe cos no room for exhaust fans
no dust filters
Setup
The gpu i used was a r9 280. all recorded about 75 deg max under Crysis 3 for 30mins, known to be one of the most demanding games on gpu. Cm130 recorded the highest at 79 deg. ambient was 30deg.
Cpu was i5 4460 and i cooled them with a single 120 Thermaltake performer 3.0. cpu cooling was ok for all cases, about 50plus under load, even cm130 was ok as there's a mini fan blowing directly on it.
Conclusion and winner
it's a close call btwn Core V1 and Node. i think depends on what u want or parts u currently have. if u run a custom loop, maybe 250d is best. but in general terms, Core and node i suppose are best. if u already have a tall cooler, then node but keep in mind the psu and gpu space.
i will say Core is the overall winner.
ITX cases can perform admirably on the cooling front. u just need to get the right one. cpu is generally not a problem unless yr doing some heavy overclocking. If u have a 'hell' setup like having the 290x, then it's all the more critical not to use certain cases, no matter how good they look.
Overclock.net has the various clubs on these cases with an huge range of pictures and posts. just search in their forum using the keywords. feel free to ask for more info.