Opinions vary, but I think it's a great kickstart/booster when you just don't have the energy to train.
If you're going for strength, though, i'd make sure to maybe up your carb/protein intake slightly on the days that you take it just to help.
i am strength training. reps at 5 with sets across, is beta alanine a worthwhile sup to take with my kind of training? just that i have read its more for aerobic/higher rep training
It wouldn't hurt, but for 5's I'm not sure how much BA will benefit you. BA tends to be for higher reps ranges as you said. However, the bottom line of what BA does is to buffer H+ ions that build up as ATP byproduct and no matter high reps/moderate intensity or high intensity/low volume as you're doing, ATP is the base molecule you're using and hydrogen+ ions will build up in the muscle to an extent in both incidences. 5 reps range doesn't tend to build up enough H+ ions to choke out the oxygen in your working muscle and disabling your ability to contract, but it wouldn't hurt and bulk BA is relatively cheap, like creatine. I suppose your rest intervals would be the biggest factor as to the relevancy of BA. If you're taking long rest between sets, then your body has all the time it needs to flush out the lactic acids/H+ ions, but if your rest intervals are short, then you could have residual lactic acids/H+ ions from the previous set that the BA would help to buffer.
I would recommend trying it. It's cheap, gives an energy boost, and reduces DOMS.
I wouldn't start with the recommended dose of 3.2g (1 tsp). Instead, start with a smaller dose and work up to a dose that you find is effective.
Personally a single dose of 1.6g pre-workout works great for me.