The LA5 is a fine plane. I wouldn't consider it an alternative to the LA7, because it lacks the top end speed and almost unmatchable OTD climb that make the LA7 so popular. You can't fly an LA5 like an LA7 and expect to be as successful.
But you still can be very successful in it. The LA5 is one of those great planes for "anything you can't ____ you can ____". Outturn or outrun/outclimb. Usually is the case. Also remember that you are a very small target an can afford to give crossing shots for an advantage later on. Remember too that enemies inexperienced with the LA5 will see the 5 designation and probably not give your plane much credit. They do not know that, although not a 7, it really is still a good performer. If you're looking for perks (or if ENY is too high), try the LA5 instead of the LA7, but remember that it is indeed a different a/c and you won't be as invincible.