To Serge or to Coverstitch...

I've been researching sergers the last 2 weeks. I want to make more clothes and it's time I return my mother's Janome 3-thread serger and get a proper 4-thread of my own.

The thing is, I'm also interested in coverstitching - as that's the best way to hem stretch fabrics and do certain types of decorative stitching. So I was going to get a combined machine. But everyone complains that it's a pain to covert the serger for coverstitching so I've been debating my options.

1) get a combo machine and potenti

ally not use all the features (if it is a pain to switch over or I'm too lazy to do it)

2) get separate machines, which costs more and takes up more room and potentially not do as much sewing as I currently feel I will...

Of course, it's possible either way that I won't sew enough to make back the investment I'd put into a serger. Especially since good models are pricy.

I'm currently deciding between the Juki MO735 (which is a serger that does coverstitch) and the Juki MO654DE (which doesn't).

I've picked Juki because I've heard the manufacture is top notch, with industrial strength materials used and a better blade than most sergers have.

Any advice or suggestions?