Sorry, but that ain't true at all. You can run a DM3 up to 19bps without drama, with an Evolve bolt they give good shot counts and there are still good boards available for peanuts. They are heavier and less efficient stock than a newer Matrix fo sure, but to say they can't keep up is daft; just lift some weights.
That said, I'd go for one of the PM5/6/7 line as the older models are now going for silly sums- just saw a PM5 go for £110 (in about three seconds), a PM6 for £210 or so and there are loads of good PM5's etc for around the £200-250 mark. You'll end up spending the thick end of that to get an older Matrix up to spec, better to pick up one of the occasional eye'd and Evolved examples that pass this way for £100 or so and use the older one for spares, or just give in and go PM/DM for easy parts availabilty, lightness and excellent shootyness all 'round.