Some of those funds are huge because they have performed pretty well, if you think they are **** which would seem odd then what would you say was worth looking at?
It's not that the funds are crap per se, it's that people buy them for all the wrong reasons and, more importantly, usually at the wrong time. When did IP High Income and Miton Spec Sits balloon in size? When markets tanked. When did BlackRock G&G balloon? When gold prices peaked. Retail investors' investment decisions are overwhelmingly driven by greed and fear.
A selection of investment funds with a rock solid, repeatable and proven investment process that outperforms the median in both rising and tumbling markets has always been the way forward, rather than flavour of the month funds run by 'star' managers whose performance waxes and wains with market movements. Nobody wants to interview Neil Woodford when equity markets are soaring because his funds are third or fourth quartile, but as soon as equity markets have a wobble, hacks are clamouring to stick a dictaphone in his face and print every thought he vocalises.
Standard Life GARS (as much as I despise Standard Life) has been a solid performer and utilises just such a process to provide solid returns, although I find their stellar performance for a self-proclaimed 'absolute return' fund to be a little concerning. I actually think their 'MyFolio' range are better as they have better diversity whilst still maintaining a GARS allocation, although they're a touch expensive.
Jupiter's Merlin funds are also a good shout, they're old-school-multimanager expensive but then their performance in all kinds of markets suggests that they're not necessarily overpriced. The first couple of funds in SEI's range have an extremely efficient use of risk, though their more aggressive portfolios are actually very inefficient in that for a lot more risk, returns between the portfolios have been near identical.
My personal favourite, however, is Russell Investments. I've yet to find a complete range of portfolios that beat them across the board in terms of efficient use of risk adjusted returns, cost of ownership or returns across a whole market cycle. That being said, my pension is invested with them.