In what sense a type of parser is less power than the other?
Assuming that by "CLR" you mean "canonical LR", then you have the order wrong; the correct containment order is

$LR(0) &lt; SLR(1) &lt; LALR(1) &lt; CLR(1)$

A possibly more meaningful way of saying that is that if we define $G_X$ to be the set of context-free grammars which can be parsed with algorithm $X$, then

$G_{LR(0)} \subset G_{SLR(1)} \subset G_{LALR(1)} \subset G_{CLR(1)}$

That containment sequence does not apply to languages. If we say that $L_X$ is the set of languages for which there is a grammar in $G_X$, then we will find that

$L_{LR(0)} \subset L_{SLR(1)} \subseteq L_{LALR(1)} \subseteq L_{CLR(1)}$

For all of these parsing algorithms, the fact that the algorithm cannot produce a conflict-free parsing table for a particular grammar means that that grammar cannot be parsed with that algorithm. The word "accept" is quite confusing here: an algorithm produces a parser from a grammar (or fails to do so); the parser then accepts those sentences which are in the grammar's language. If an algorithm produces a parser for a grammar, then that parser will be 100% precise: it will accept all sentences in that grammar's language and reject all other sentences. 

Furthermore, all these LR parsers have linear time and space complexity (in the size of the sentence to be recognised), and all of them reject invalid inputs at the earliest possible point, which is as soon as the prefix of the input cannot be the prefix of any sentence in the language. It is true that some of the parsers may perform extra reduce actions before reporting failure, but that is not considered in the definition of a grammar's "power".