ok im going to throw in my 10 cents here.
I am brutally efficient with weight training

Apart from a couple of warmup sets to get your body ready for the lifts Pyramiding your weight from 70 to 90 is a complete waste of time and is impeding your muscular development massively.
instead using squats as en example:

warmup set of 10 reps with 40kg
warmup set of 5 reps with 70kg
Your body is now ready for a maximal effort of 2 sets of 10 with 90kg

5 reps in my experience is a bad range--yes i know its touted as the 6 rep strength range but the weight you are able to use for a maximal effort of 5 reps doesnt allow you to get a good feel for the exercise, puts you closer to injury and usually instigates crap form

Take notes on your iphone, paper of exactly what you do for each exercise and next week you hit it-- aim to better it-- i cannot emphasis how awesome this is for progressing, i will make double the progress of anyone else at the gym by doing this because no effort at all is wasted-plus if i cannot make the improvment for 2 weeks in a row its a good sign to me that my diet isnt in check and/or i am over training.
keeping notes ==massive

2 sets of maximal squats will totally burn me out and leave me lieing on the floor for 5 minutes after each set feeling like ive just lost 2 years off my life. -- HIT to the max!

so you wanna lose weight:
Compund lifts = very good! yay multiple muscular involvment = maximal calorie burning both during the exercise and afterwards-- the more muscle you carry the more calories you burn AT REST--muscle is highly metabolically active, fat is not active
so in a nutshell the more muscle you carry the easier you will find it to burn fat while lieing in bed!

If you need to shift a serious amount of fat keep up with the compounds, but the real action is in your diet and getting some low intensity cardio every day first thing on an empty stomach

but there is nothing wrong with what you are doing, any exercise is good, it just depends on what your goals are and wether you want to cut all the crap out and get there sooner rather than later