I am a native Scottish English speaker, and I know German and Latin. Spanish seems to be the most regular of the Romance languages, orthography-wise, and it also seems quite simple when compared to French. Also, grammatical gender can also be called noun class, maybe this would be a better convention to use? Also, Spanish only has masculine and feminine, and I don't think it declines for case. German, to compare, has masculine, feminine and neuter, and words can decline in nominative, accusative and dative cases. Polish has 5 genders: animate masculine, inaninate masculine, personal masculine, feminine and neuter. I suppose you could argue that Spanish is better in terms of grammatical simplicity, but it all depends on the person learning it.

Another point I'd like to make is the fact that languages do not have "flaws". Languages are simply finite tools for communicating an infinite amount of data, and no language is inherently better than another.