I think people are overreacting concerning the Renault engine.
Last I checked they have won the WDC and WCC 4 years straight and between RBR and Lotus and Williams in the past few years have produced very reliable and competitive engines. Plus they have a history with turbo power plants and the likes compared to say Mercedes. If there is fault to be assigned, it will have to go down to the teams IMO. plus these are early days and if I were to speculate on Lotus, the engine is probably not the problem.

Caterham were always going to produce a conservative car and STR and RBR are probably closer in design than most suspect. At least from a fundamental platform. Given that they are owned by the seam folks and are both running the same engine package.

Its also early days, so lets see what happens by the time we get to Australia. Of course I hope that RBR are pegged down a notch and that their issues are down to the tight packaging and not the engine.